Devices for treating the spine

ABSTRACT

Various features of spinal implants and systems and methods for implanting the same with or between tissue layers in the human body.

The present application is a continuation-in-part of U.S. patentapplication Ser. No. 11/464,782, a continuation-in-part of U.S. patentapplication Ser. No. 11/464,790, a continuation-in-part of U.S. patentapplication Ser. No. 11/464,793, a continuation-in-part of U.S. patentapplication Ser. No. 11/464,807, a continuation-in-part of U.S. patentapplication Ser. No. 11/464,812 and a continuation-in-part of U.S.patent application Ser. No. 11/464,815, all of which were filed on Aug.15, 2006, and claim the benefit of U.S. Provisional Application No.60/708,691, filed Aug. 16, 2005, U.S. Provisional Application No.60/738,432, filed Nov. 21, 2005 and U.S. Provisional Application No.60/784,185, filed Mar. 21, 2006, all of the above are incorporatedherein by reference. In addition to claiming the benefit of the filingdates of all of the above regular and provisional applications, thepresent application also claims the benefit of U.S. Provisional PatentApplication No. 60/890,868, filed Feb. 21, 2007 and, U.S. ProvisionalPatent Application No. 60/936,974, filed Jun. 22, 2007, all of which areincorporated herein by reference.

FIELD OF THE INVENTION

The present subject matter generally relates to apparatus and methodsemployed in minimally invasive surgical procedures and more particularlyto various aspects of apparatus and methods for separating and/orsupporting tissue layers, especially in the spine.

BACKGROUND OF THE INVENTION

A variety of physical conditions involve two tissue surfaces that, fordiagnosis or treatment of the condition, need to be separated ordistracted or maintained in a separated condition from one another andthen supported in a spaced-apart relationship. Such separation ordistraction may be to gain exposure to selected tissue structures, toapply a therapeutic pressure to selected tissues, to return orreposition tissue structures to a more normal or original anatomicposition and form, to deliver a drug or growth factor, to alter,influence or deter further growth of select tissues or to carry outother diagnostic or therapeutic procedures. Depending on the conditionbeing treated, the tissue surfaces may be opposed or contiguous and maybe bone, skin, soft tissue, or a combination thereof.

One such a condition that occurs in the orthopedic field is vertebralcompression fractures. Vertebral compression fractures affect asignificant part of the population, and add significant cost to thehealth care system. A vertebral compression fracture is a crushing orcollapsing injury to one or more vertebrae. Vertebral fractures aregenerally but not exclusively associated with osteoporosis, metastasis,and/or trauma. Osteoporosis reduces bone density, thereby weakeningbones and predisposing them to fracture. The osteoporosis-weakenedvertebrae can collapse during normal activity and are also morevulnerable to injury from shock or other forces acting on the spine. Insevere cases of osteoporosis, actions as simple as bending forward canbe enough to cause a vertebral compression fracture. Vertebralcompression fractures are the most common type of osteoporotic fracturesaccording to the National Institute of Health.

The mechanism of such vertebral fractures is typically one of flexionwith axial compression where even minor events can cause damage to theweakened bone. While the fractures may heal without intervention, thecrushed bone may fail to heal adequately. Moreover, if the bones areallowed to heal on their own, the spine may be deformed to the extentthe vertebrae were compressed by the fracture. Spinal deformity may leadto breathing and gastrointestinal complications, and adverse loading ofadjacent vertebrae.

One technique used to treat vertebral compression fractures is injectionof bone filler into the fractured vertebral body. This procedure iscommonly referred to as percutaneous vertebroplasty. Vertebroplastyinvolves injecting bone filler (for example, bone cement, allographmaterial or autograph material) into the collapsed vertebra to stabilizeand strengthen the crushed bone.

In vertebroplasty, physicians typically use one of two surgicalapproaches to access thoracic and lumbar vertebral bodies:transpedicular or extrapedicular. The transpedicular approach involvesthe placement of a needle or wire through the pedicle into the vertebralbody, and the physician may choose to use either a unilateral access orbilateral transpedicular approach. The extrapedicular technique involvesan entry point through the posterolateral corner of the vertebral body.

Regardless of the surgical approach, the physician generally places asmall diameter guide wire or needle along the path intended for the bonefiller delivery needle. The guide wire is advanced into the vertebralbody under fluoroscopic guidance to the delivery point within thevertebra. The access channel into the vertebra may be enlarged toaccommodate the delivery tube. In some cases, the delivery tube isplaced directly into the vertebral body and forms its own opening. Inother cases, an access cannula is placed over the guide wire andadvanced into the vertebral body. After placement, the cannula isreplaced with the delivery tube, which is passed over the guide wire orpin. In both cases, a hollow needle or similar tube is placed throughthe delivery tube into the vertebral body and used to deliver the bonefiller into the vertebra.

In this procedure, the use of lower viscosity bone filler and higherinjection pressures tend to disperse the bone filler throughout thevertebral body. However, such procedures dramatically increase the riskof bone filler extravasation from the vertebral body. The difficulty ofcontrolling or stopping bone filler flow into injury-sensitive areasincreases as the required pressure increases. Thus, caution must stillbe taken to prevent extravasation with the greatest attention given topreventing posterior extravasation because it may cause spinal cordtrauma. Physicians typically use repeated fluoroscopic imaging tomonitor bone filler propagation and to avoid flow into areas of criticalconcern. If a foraminal leak results, the patient may require surgicaldecompression and/or suffer paralysis.

Another type of treatment for vertebral fractures is known asKyphoplasty. Kyphoplasty is a modified vertebral fracture treatment thatuses one or two balloons, similar to angioplasty balloons, to attempt toreduce the fracture and, perhaps, restore some vertebral height prior toinjecting the bone filler. One or two balloons are typically introducedinto the vertebra via bilateral transpedicular cannula. The balloons areinflated to reduce the fracture. After the balloon(s) are deflated andremoved, leaving a relatively empty cavity, bone cement is injected intothe vertebra. In theory, inflation of the balloons may restore somevertebral height. However, in practice it is difficult to consistentlyattain meaningful and predictable height restoration. The inconsistentresults may be due, in part, to the manner in which the balloon expandsin a compressible media, such as the cancellous tissue within thevertebrae, and the structural orientation of the trabecular bone withinthe vertebra, although there may be additional factors as well.

Thus there is a need for devices and methods to treat the abovementioned diseases, in particular compression vertebral fractures.

Another location of the body where tissue separation is useful as acorrective treatment is in the spinal column. Developmentalirregularities, trauma, tumors, stress and degenerative wear can causedefects in the spinal column for which surgical intervention isnecessary. Some of the more common defects of the spinal column includevertebral compression fractures, degeneration or disruption of anintervertebral disk and intervertebral disk herniation. These and otherpathologies of the spine are often treated with implants that canrestore vertebral column height, immobilize or fuse adjacent vertebralbones, or function to provide flexibility and restore natural movementof the spinal column. Accordingly, different defects in the spinalcolumn require different types of treatment, and the location andanatomy of the spine that requires corrective surgical proceduresdetermines whether an immobilizing implantable device or a flexibleimplantable device is used for such treatment.

In a typical spinal corrective procedure involving distraction of tissuelayers, damaged spinal tissue is removed or relocated prior todistraction. After the damaged tissue has been removed or relocated,adjacent spinal tissue layers, such as adjacent bone structures, arethen distracted to separate and restore the proper distance between theadjacent tissue layers. Once the tissue layers have been separated bythe proper distance, an immobilizing or flexible device, depending onthe desired treatment, is implanted between the tissue layers. In thepast, the implantable treatment devices have been relatively largecage-like devices that require invasive surgical techniques whichrequire relative large incisions into the human spine. Such invasivesurgical techniques often disrupt and disturb tissue surrounding thesurgical site to the detriment of the patient.

Therefore, there remains a need for implantable treatment devices andmethods that utilize minimally invasive procedures.

Such methods and devices may be particularly needed in the area ofintervertebral or disk treatment. The intervertebral disk is dividedinto two distinct regions: the nucleus pulposus and the annulusfibrosus. The nucleus lies at the center of the disk and is surroundedand contained by the annulus. The annulus contains collagen fibers thatform concentric lamellae that surround the nucleus and insert into theendplates of the adjacent vertebral bodies to form a reinforcedstructure. Cartilaginous endplates are located at the interface betweenthe disk and the adjacent vertebral bodies.

The intervertebral disk is the largest avascular structure in the body.The cells of the disk receive nutrients and expel waste by diffusionthrough the adjacent vascularized endplates. The hygroscopic nature ofthe proteoglycan matrix secreted by cells of the nucleus operates togenerate high intra-nuclear pressure. As the water content in the diskincreases, the intra-nuclear pressure increases and the nucleus swellsto increase the height of the disk. This swelling places the fibers ofthe annulus in tension. A normal disk has a height of about 10-15 mm.

There are many causes of disruption or degeneration of theintervertebral disk that can be generally categorized as mechanical,genetic and biochemical. Mechanical damage includes hemiation in which aportion of the nucleus pulposus projects through a fissure or tear inthe annulus fibrosus. Genetic and biochemical causes can result inchanges in the extracellular matrix pattern of the disk and a decreasein biosynthesis of extracellular matrix components by the cells of thedisk. Degeneration is a progressive process that usually begins with adecrease in the ability of the extracellular matrix in the centralnucleus pulposus to bind water due to reduced proteoglycan content. Witha loss of water content, the nucleus becomes desiccated resulting in adecrease in internal disk hydraulic pressure, and ultimately to a lossof disk height. This loss of disk height can cause the annulus to bucklewith non-tensile loading and the annular lamellae to delaminate,resulting in annular fissures. Herniation may then occur as ruptureleads to protrusion of the nucleus.

Proper disk height is necessary to ensure proper functionality of theintervertebral disk and spinal column. The disk serves severalfunctions, although its primary function is to facilitate mobility ofthe spine. In addition, the disk provides for load bearing, loadtransfer and shock absorption between vertebral levels. The weight ofthe person generates a compressive load on the disks, but this load isnot uniform during typical bending movements. During forward flexion,the posterior annular fibers are stretched while the anterior fibers arecompressed. In addition, a translocation of the nucleus occurs as thecenter of gravity of the nucleus shifts away from the center and towardsthe extended side.

Changes in disk height can have both local and global effects. On thelocal (or cellular, level) decreased disk height results in increasedpressure in the nucleus, which can lead to a decrease in cell matrixsynthesis and an increase in cell necrosis and apoptosis. In addition,increases in intra-discal pressure create an unfavorable environment forfluid transfer into the disk, which can cause a further decrease in diskheight.

Decreased disk height also results in significant changes in the globalmechanical stability of the spine. With decreasing height of the disk,the facet joints bear increasing loads and may undergo hypertrophy anddegeneration, and may even act as a source of pain over time. Increasedstiffness of the spinal column and increased range of motion resultingfrom loss of disk height can lead to further instability of the spine,as well as back pain.

Radicular pain may result from a decrease in foraminal volume caused bydecreased disk height. Specifically, as disk height decreases, thevolume of the foraminal canal, through which the spinal nerve rootspass, decreases. This decrease may lead to spinal nerve impingement,with associated radiating pain and dysfunction

Finally, adjacent segment loading increases as the disk height decreasesat a given level. The disks that must bear additional loading are nowsusceptible to accelerated degeneration and compromise, which mayeventually propagate along the destabilized spinal column.

In spite of all of these detriments that accompany decreases in diskheight, where the change in disk height is gradual many of the illeffects may be “tolerable” to the spine and patient and may allow timefor the spinal system to adapt to the gradual changes. However, thesudden decrease in disk volume caused by herniation which requiressurgical removal of the disk or disk nucleus may increase the local andglobal problems noted above.

Many disk defects are treated through a surgical procedure, such as adiscectomy in which the nucleus pulposus material is removed. During atotal discectomy, a substantial amount (and usually all) of the volumeof the nucleus pulposus is removed and immediate loss of disk height andvolume can result. Even with a partial discectomy, loss of disk heightcan ensue. Discectomy alone is the most common spinal surgicaltreatment, frequently used to treat radicular pain resulting from nerveimpingement by disk bulge or disk fragments contacting the spinal neuralstructures.

The discectomy may be followed by an implant procedure in which aprosthesis is introduced into the cavity left in the disk space when thenucleus material is removed. Thus far, the most common prosthesis is amechanical device or a “cage” that is sized to restore the proper diskheight and is configured for fixation between adjacent vertebrae. Thesemechanical solutions take on a variety of forms, including solidkidney-shaped implants, hollow blocks filled with bone growth material,push-in implants and threaded cylindrical cages.

A challenge in the use of a posterior procedure to install spinalprosthesis devices is that a device large enough to contact the endplates and expand the space between the end plates of the same oradjacent vertebra must be inserted through a limited space. In the caseof procedures to increasing intervertebral spacing, the difficulties arefurther increased by the presence of posterior osteophytes, which maycause “fish mouthing” or concavity of the posterior end plates andresult in very limited access to the disk. A further challenge indegenerative disk spaces is the tendency of the disk space to assume alenticular shape, which requires a relatively larger implant than oftenis difficult to introduce without causing trauma to the nerve roots. Thesize of rigid devices that may safely be introduced into the disk spaceis thereby limited.

While cages of the prior art have been generally successful in promotingfusion and approximating proper disk height, typically these cages havebeen inserted from the posterior approach, and are therefore limited insize by the interval between the nerve roots. Further, it is generallydifficult, if not impossible to implant from the posterior approach acage that accounts for the natural lordotic curve of the lumber spine.

It is desirable to reduce potential trauma to the nerve roots and yetstill allow restoration or maintenance of disk space height inprocedures involving vertebrae fusion devices and disk replacement,containment of the nucleus of the disk or prevention of herniation ofthe nucleus of the disk. In general minimally invasive surgicaltechniques reduce surgical trauma, blood loss and pain. However, despitethe use of minimally invasive techniques, the implantation of cagedevices for treating the spine typically involves nerve root retraction,an inherently high risk procedure. It is therefore desirable to reducethe degree of invasiveness of the surgical procedures required toimplant the device, which may also serve to permit reduction in thepain, trauma, and blood loss as well as the avoidance and/or reductionof the nerve root retraction.

In minimally invasive procedures, to monitor placement, it is usefulthat implant devices inserted into spinal tissue be detectable usingfluoroscopic imaging systems. However if a device is visible using X-raytechnology, then the device can interfere with the detection andmonitoring of spinal tissues, such as bone growing into the disk spaceafter a vertebral fusion procedure. Additional advances would also beuseful in this area.

SUMMARY OF INVENTION

The present invention relates to various aspects of distraction systemsand methods for separating, supporting or both separating and supportingtissue layers in the human body.

One aspect of the present disclosure relates to a spinal implantincluding a generally elongated member having a first configuration forinsertion between spinal tissue layers and a second configurationin-situ in which the elongated member curves to form a distractionstructure that engages and distracts spinal tissue. The elongated memberhas a first extent in a direction extending between the spinal tissuelayers and the distraction structure has a second extent in thedirection extending between the tissue layers. The second extent of thedistraction structure is greater than the first extent of the elongatedmember.

Another aspect of the present disclosure relates to a spinal implantsystem including a guide member adapted for insertion into spinal tissueand a generally elongated member advanceable along the guide member. Theguide member is adapted for guiding the elongated member to a locationbetween spinal tissue layers and into a shape in-situ of a supportstructure that separates, supports or both separates and supports thespinal tissue layers.

Yet another aspect of the present disclosure relates to a spinal implantdeployment system including a first cannula having a proximal endportion, a distal end portion and a passageway therethrough. The distalend portion of the first cannula includes an opening in communicationwith the passageway and is adapted for insertion into or between spinaltissue layers. The deployment system also includes a guide member thathas a distal end portion that is advanceable through the passageway andthe opening of the first cannula for deployment into or between spinaltissue layers. Additionally, the deployment system includes an elongatedmember adapted for advancement along the guide member and through thepassageway and the opening of the first cannula for deployment into orbetween tissue layers. The elongated member is guided by the guidemember to form a support structure in-situ wherein the support structureseparates, supports (or both) and spinal tissue layers.

Yet a further aspect of the present invention relates to a spinalimplant comprising an implantable member that is adapted forimplantation into or between spinal tissues. The implantable member iscomprised of a thermoplastic material and is substantiallyincompressible in a first direction and substantially flexible in asecond direction that is generally perpendicular to the first direction.

Another aspect of the present disclosure relates to a device fortreating an intervertebral disk comprising a guide member that isinsertable into the intervertebral disk, preferably between the annulusand nucleus of the disk. The guide member has a pre-deployedconfiguration for insertion into the disk and a deployed configurationin which the guide member at least partially surrounds at least aportion of the nucleus. The device also includes at least one elongatedmember advanceable along the guide member and positionable within thedisk.

Yet another aspect of the present disclosure relates to a device fortreating an intervertebral disk comprising an elongated member that isinsertable into an intervertebral disk, preferably between the annulusand nucleus of the disk. The elongated member has a pre-deployedconfiguration for insertion into the disk and a deployed configurationin which the elongated member forms a structure that at least partiallysurrounds the nucleus. The structure is adapted to substantially containthe nucleus within the annulus.

Yet a further aspect of the present disclosure is related to a devicefor treating an annulus of an intervertebral disk comprising anelongated member that is insertable into the annulus of anintervertebral disk. The elongated member has a pre-deployedconfiguration for insertion into the annulus and a deployedconfiguration in which the elongated member forms a support structurethat supports the annulus.

Yet another aspect of the present invention relates to a device fordelivering flowable material into spinal tissue. The device includes adelivery tube that has a proximal end portion and a distal end portion.The proximal end portion is adapted to be operatively connected to asupply of flowable material. The distal end portion of the delivery tubehas a first linear pre-delivery configuration for insertion into spinaltissue and a second curved delivery configuration within the spinaltissue for the directional delivery of flowable material.

Yet a further aspect of the present disclosure relates to a method oftreating the human spine comprising inserting at least the distal endportion of a guide member between tissue layers of the human spine. Theconfiguration of the distal portion of the guide member is then changedin-situ to define a predetermined shape. An elongated member is thenadvanced over at least the distal end portion of the guide member sothat the elongated member substantially assumes the predetermined shapeof the distal end portion of the guide member to form a supportstructure between the tissue layers.

A further aspect of the present disclosure relates to a method oftreating an intervertebral disk comprising inserting a distal endportion of a guide member into the intervertebral disk, preferablybetween an annulus and nucleus of the disk. The shape of the distal endportion of the guide member is then changed in-situ. A first generallyelongated member is advanced over the distal end portion of guide memberto a location within the disk and the first generally elongated memberdefines a containment structure that assists in substantially containingthe nucleus within the annulus.

Another aspect of the present disclosure relates to a method of treatingan intervertebral disk comprising inserting a generally elongated memberinto an intervertebral disk, preferably between the annulus and thenucleus of the disk. The configuration of the elongated member is thenchanged in-situ to define a structure that assists in substantiallycontaining the nucleus within the annulus.

A further aspect of the present disclosure relates to a method ofrepairing an annulus of an intervertebral disk comprising inserting agenerally elongated member into an annulus of an intervertebral disk.The configuration of the elongated member is then changed in-situ todefine a coil-like structure that assists in substantially containingthe nucleus within the annulus.

BRIEF DESCRIPTION OF THE FIGURES

In the course of this description, reference will be made to theaccompanying drawings, wherein:

FIG. 1 is a partial side view of a normal human vertebral column;

FIG. 2 is comparable to FIG. 1, but shows a vertebral compressionfracture in one of the vertebral bodies;

FIG. 3 is a top view of a vertebra with an endplate partially removed;

FIG. 4 is a side view of the vertebra of FIG. 3;

FIG. 5 is a perspective view of one embodiment of a distraction devicesupport structure defined by an elongated member that has a coil-like ora spring configuration;

FIG. 6 is a partial cross-sectional side view one embodiment of adelivery system for deploying the distraction device of FIG. 5;

FIG. 7 is a partial cross-sectional side view of the distraction devicedelivery system of FIG. 6, shown with the distraction device partiallyadvanced over a coiled section of a guide member;

FIG. 8 is a partial cross-sectional side view of the distraction devicedelivery system of FIG. 6, shown with the distraction devicesubstantially advanced over the coiled section of the guide member;

FIGS. 9-19 are perspective views of different embodiments of distractiondevices and support structures formed therefrom, showing a variety ofshapes and cross-sectional profiles;

FIG. 20 is a perspective view of a vertebra with the superior endplateremoved to show the delivery of a guide member into the vertebral body;

FIG. 21 is a perspective view of the vertebra of FIG. 20 shown with adistraction device and pusher mounted on the guide member;

FIG. 22 is a perspective view of the vertebra of FIG. 20 shown with thedistraction device partially advanced or deployed within the vertebralbody;

FIG. 23 is a perspective view of the vertebra of FIG. 20 shown with thedistraction device substantially fully deployed within the vertebralbody;

FIG. 24 is a side cross-sectional view of the vertebra of FIG. 20, withthe distraction device fully deployed within the vertebral body;

FIGS. 25-29 illustrate a method of incremental deployment of thedistraction device;

FIG. 30 is a perspective view of one embodiment of a flowable materialdelivery device in a first configuration;

FIG. 31 is a perspective view of the flowable material delivery deviceof FIG. 30 in a second configuration;

FIG. 32 is a perspective view of vertebra having flowable materialdelivered therein;

FIG. 33 is a side view of one embodiment of a distal end portion of adeployment cannula;

FIG. 34 is a perspective view of the distal end portion of thedeployment cannula of FIG. 33, shown with a guide member being deployedfrom therefrom;

FIG. 35 is a side view of another embodiment of a distal end portion ofa deployment cannula;

FIG. 36 is a cross-sectional view of the distal end portion of thedeployment cannula of FIG. 33, shown with a distraction device beingdeployed therefrom;

FIG. 37 is a perspective view of another embodiment of a distal endportion a deployment cannula;

FIG. 37A is a cross-sectional view of the deployment cannula of FIG. 37,shown with a distraction device located therein;

FIG. 38 is a perspective view of one embodiment of a distal end portionof a working cannula;

FIG. 39 is a perspective view of the working cannula of FIG. 38 with thedeployment cannula of FIG. 37 inserted therein and, shown with thedeployment cannula and working cannula in a first position;

FIG. 40 is a perspective view of the combination of the deploymentcannula and working cannula of FIG. 39, shown in a second position andhaving a guide member extending therefrom;

FIG. 41 is a perspective view of the combination of the deploymentcannula and working cannula of FIG. 40, shown in the first position andhaving a guide member extending therefrom;

FIG. 42 is a perspective view of the combination of the deploymentcannula and working cannula of FIG. 40, shown in the first position andhaving a distraction device being deployed therefrom;

FIGS. 43-64 are various illustrations of different embodiments of thedistal end portion of a distraction device;

FIG. 65 is a perspective view of another embodiment of a distractiondevice;

FIG. 66 is a perspective view of a distraction device support structurethat is defined by the distraction device of FIG. 65;

FIG. 67 is a perspective view of another embodiment of a distractiondevice and distraction device support structure;

FIG. 68 is a perspective view of another embodiment of a distractiondevice and distraction device support structure;

FIG. 69 is a partial cross-sectional view of the distraction devicesupport structure of FIG. 68;

FIGS. 70, 71 and 72 are illustrations of various embodiments ofprotrusions that can extent from the distraction device;

FIG. 73 is a perspective view of another embodiment of a distractiondevice;

FIG. 74 is a perspective view of a distraction device support structuredefined by the distraction device of FIG. 73;

FIG. 75 is a partial cross-sectional view of the distraction devicesupport structure of FIG. 74;

FIG. 76 is a perspective view of another embodiment of a distractiondevice;

FIG. 77 is a cross-sectional view of a support structure defined by thedistraction device of FIG. 76;

FIG. 78 is a cross-sectional view of the support structure of FIG. 77;

FIG. 79 is a cross-sectional view of a support structure defined byanother embodiment of a distraction device;

FIG. 80 is a cross-sectional view of the support structure of FIG. 79;

FIG. 81 is a cross-sectional view of a support structure defined byanother embodiment of a distraction device;

FIG. 82 is a cross-sectional view of the support structure of FIG. 81;

FIG. 83A is a perspective view of another embodiment of a distractiondevice;

FIG. 83B is a side view of the support structure defined by thedistraction device of FIG. 83A;

FIG. 83C is a side view of the support structure of FIG. 83B;

FIG. 84 is a perspective view of another embodiment of a distractiondevice, shown with the teeth in an unlocked position;

FIG. 85 is a perspective view of the distraction device of FIG. 84,shown with the teeth in a locked position;

FIG. 86 is a perspective view of another embodiment of a distractiondevice, shown with the teeth in an unlocked position;

FIG. 87 is a perspective view of the distraction device of FIG. 86,shown with the teeth in a locked position;

FIG. 87A is a perspective view of another embodiment of a distractiondevice that includes a reinforcing member that assists in maintainingthe distraction device in the shape of the support structure;

FIG. 88 is a perspective view of another embodiment of a distractiondevice and distraction device support structure;

FIG. 89 is a cross-sectional view of a vertebra shown with thedistraction device of FIG. 88 defining a support structure therein;

FIG. 90 is a cross-sectional view of a vertebra shown with a distractiondevice support structure deployed therein and flowable material locatedon the superior side of the distraction device support structure;

FIG. 91 is a top view of another embodiment of a distraction device anddistraction device support structure;

FIG. 92 is a schematic illustration of the relationship between theteeth of the distraction device of FIG. 91;

FIG. 93 is a top view of another embodiment of a distraction device anddistraction device support structure;

FIG. 94 is a schematic illustration of the relationship between theteeth of the distraction device of FIG. 93;

FIG. 95 is a perspective view of another embodiment of a distractiondevice defining a distraction device support structure;

FIG. 96 is a side view of the distal end portion of the distractiondevice of FIG. 95;

FIG. 97 is a perspective view of the distraction device of FIG. 96,shown initially deployed over a guide member to form the distractiondevice support structure of FIG. 95;

FIG. 98 is a perspective view of the distraction device of FIG. 96,shown further deployed over the guide member to form the distractiondevice support structure of FIG. 95;

FIG. 99 is a perspective view of one embodiment of a guide member;

FIGS. 100-104 illustrate different embodiments of the distal end portionof the guide member;

FIG. 105 is a perspective view one embodiment of a cutting member whichcan be advanced along a guide member;

FIG. 106 is perspective view of a vertebra having the cutting member ofFIG. 105 deployed therein;

FIG. 107 is a cross-sectional view of another embodiment of adistraction device;

FIG. 108 is a cross-sectional view of the distraction device of FIG.107, shown in a compressed configuration;

FIG. 109 is a top cross-sectional view of the intervertebral disk, shownwith a distraction device partially advanced over the guide memberwithin the nucleus space;

FIG. 110 is a top cross-sectional view of the intervertebral disk ofFIG. 109, shown with the distraction device defining a support structurewithin the nucleus space;

FIG. 111 is a side partial cross-sectional view of the intervertebraldisk of FIG. 109, shown with the distraction device deployed therein andunder a compressive load;

FIG. 112 is a side partial cross-sectional view of the intervertebraldisk of FIG. 109, shown with the distraction device deployed therein;

FIG. 113 is a perspective view of a damaged intervertebral disk havingan annular fissure;

FIG. 114 is a top view of an intervertebral disk, shown with a guidemember deployed therein;

FIG. 115 is a perspective view of the intervertebral disk of FIG. 114,shown with a containment device deployed over the guide member;

FIG. 116 is a top view of the intervertebral disk of FIG. 114, shownwith the containment device deployed therein;

FIGS. 117-120 illustrate different embodiment of cross-sectionalprofiles of the containment device;

FIG. 121 is a perspective view of an intervertebral disk, shown with aguide member and containment device deployed over the guide member;

FIG. 122 is a perspective view of a guide member and containment device;

FIG. 123 is a perspective view of the intervertebral disk of FIG. 121,shown with a containment device deployed therein;

FIG. 124 is a perspective view of the intervertebral disk of FIG. 121,shown with a containment device deployed over a guide member;

FIG. 125 is a perspective view of the intervertebral disk of FIG. 121,shown with a containment device deployed therein;

FIG. 126 is a perspective view of an intervertebral disk, shown with adeployment cannula deployed therein;

FIG. 127 is a perspective view of the intervertebral disk of FIG. 126,shown with an annulus repair device deployed within the annulus;

FIG. 128 is a perspective view of one embodiment of an annulus repairdeployment system;

FIG. 129 is a perspective view of the deployments system of FIG. 128,shown in a coiled configuration;

FIG. 130 is a perspective view of the deployment system of FIG. 128,shown in coiled configuration;

FIG. 131 is a side view of another embodiment of the nucleus containmentdevice; and

FIG. 132 is a perspective view of the nucleus containment device of FIG.131 deployed within an intervertebral disk.

DETAILED DESCRIPTION

The devices and methods of the present invention provide multiplefeatures of spinal implants, such as distraction devices, distractiondevice support structures and deployment systems that can be used toactively separate tissue layers by engaging them and forcing them apart,or to support the separation of tissue layers separated by thedistraction device itself or by other devices or processes or acombination of these.

As used herein, the terms “distraction device” and “distraction devicesupport structure” are intended to have a general meaning and are notlimited to devices that only actively separate tissue layers, onlysupport tissue layers or only both actively separate and support tissuelayers. For example, the distraction device and support structure ingeneral can be used to actively separate layers of tissue and then beremoved after such separation, or the distraction device and the supportstructure could be used to support layers of tissue that have beenpreviously separated by a different device. Alternatively, thedistraction device and support structure can be used to activelyseparate the layers of tissue and remain in place to support the layersof tissue in order to maintain such separation. Unless more specificallyset forth in the claims, as used herein, “distraction device” and“distraction device support structure” encompasses any and all of these.

It should also be understood that various embodiments of the device,system and method of the present subject matter are illustrated forpurposes of explanation in the treatment of vertebral compressionfractures, height restoration of a diseased disk, vertebral fusionprocedures, replacement of removed disks or vertebra, intervertebraldisk nucleus containment or annulus fibrous repair. However, in itsbroader aspects, the various features of the present invention are notlimited to these particular applications and may be used in connectionwith other tissue layers, such as soft tissue layers, although it hasparticular utility and benefit in treatment of vertebral conditions.

FIG. 1 illustrates a section of a healthy vertebral (spinal) column,generally designated as 100, without injury. The vertebral column 100includes adjacent vertebrae 102, 102 a and 102 b and intervertebraldisks 104, 104 a, 104 b and 104 c separating the adjacent vertebrae.

FIGS. 3 and 4 illustrate in more detail a normal vertebra and itsattributes. The vertebra, generally designated as 102, includes avertebral body 106 that is roughly cylindrically and comprised of innercancellous bone 108 surrounded by the cortical rim 110, which iscomprised of a thin layer of cortical compact bone. The cortical rim 110can be weakened by osteoporosis and may be fractured due to excessivemovement and/or loading. The body 106 of the vertebra is capped at thetop by a superior endplate 112 and at the bottom by an inferior endplate114, made of a cartilaginous layer. To the posterior (or rear) of thevertebral body 106 is the vertebral foramen 116, which contains thespinal cord (not shown). On either side of the vertebral foramen 116 arethe pedicles 118, 118 a, which lead to the spinal process 120. Otherelements of the vertebra include the transverse process 122, thesuperior articular process 124 and the inferior articular process 126.

FIG. 2 illustrates a damaged vertebral column, generally designated as128, with a vertebral body 130 of a vertebra 132 suffering from acompression fracture 134. The vertebral body 130 suffering from thecompression fraction 134 becomes typically wedge shaped and reduces theheight of both the vertebra 132 and vertebral column 128 on the anterior(or front) side. As a result, this reduction of height can affect thenormal curvature of the vertebral column 128.

FIG. 5 illustrates one embodiment of a spinal implant or distractiondevice 136 in accordance with the present subject matter. In thisembodiment, the distraction device 136 is comprised of an elongatedmember, such as a thread or ribbon, made from biocompatible materialsthat are suitable for long term implantation into human tissue in thetreatment of degenerative tissue, trauma or metastatic conditions orwhere a tissue distraction device is needed. The biocompatible materialsmay be calcium phosphate, tricalcium phosphate, hydroxyapatite,polyetheretherketones (PEEK), nylon, Nitinol (NiTi) or any othersuitable biocompatible material. The material may be solid or porous fortissue ingrowth, and may elute therapeutic or growth enhancing agents.One of the advantages of using biological or biocompatible material totreat vertebral compression fractures is that these elements have a morenatural like substance. However, other materials could be used and stillbe within the scope of the present invention.

Referring to FIGS. 5 and 6, distraction device 136 or spinal implant hasa generally rectangular cross-section defined by a top surface 138, abottom surface 140 and first and second sidewalls 142 and 144. However,as described in more detail below, the distraction device can have avariety of shapes and profiles. Distraction device 136 also includes aplurality of alternating recesses or slots 146 and projections or teeth148 spaced along the length of the distraction device. Furthermore,distraction device 136 is substantially rigid or incompressible in afirst dimension or direction between the top surface 138 and bottomsurface 140, and substantially flexible in a second dimension ordirection that is generally perpendicular to the first dimension andextends along the length of the distraction device. As explained in moredetail below, recesses 146 can facilitate flexibility of distractiondevice 136 in the second dimension.

When deployed between tissue layers, distraction device 136 curves orflexes to define a structure 150, such as a support structure, that hasa multi-tiered arrangement, such as a scaffolding or platform, thatserves to actively separate or support (or both) opposed tissue layersas shown in FIGS. 5, 8, 23 and 24. Referring to FIG. 5, distractiondevice 136, as deployed, has a helical, coil or spring-likeconfiguration. As illustrated, the distraction device defines a helicalconfiguration with a tight pitch forming an essentially hollow cylinderor cage. Each turn or winding 151 is wound on top of the perviouswinding 151 a to form a plurality of stacked windings or tiers in whichtop surface 138 and bottom surface 140 of distraction device 136 are incontact or have little or no spacing therebetween. Because distractiondevice 136 is substantially rigid in the first dimension between top andbottom surfaces 138, 140, in this deployed configuration, thedistraction device forms a very stiff column or structure 150 along theaxis of a center line of the coil or spring-like structure.

In one embodiment, structure 150 includes or defines an innerspace orresident volume 152. As used herein, “resident volume” refers generallyto a structural characteristic of the support structure. The residentvolume is a volume that is generally defined by the distraction device,when it is in the deployed configuration. The resident volume is notnecessarily a volume completely enclosed by the distraction device andcan be any volume generally defined by the distraction device. This termdoes not necessarily mean that the resident volume is an open or voidvolume or cavity and does not preclude a situation in which the residentvolume is, at some point in time, filled with another material, such asbone filler, cement, therapeutic drugs or the like. It also does notpreclude the resident volume from containing undisturbed human tissuethat is located or remains within the resident volume during or afterdeployment of the distraction device, as will be explained in moredetail below. For example, if the distraction device is employed toseparate adjoining soft tissue layers, such as subcutaneous fat andunderlying muscle tissue, the resident volume of the distraction devicemay be hollow or void of tissue after separation. On the other hand, ifinserted into a vertebra having cancellous bone tissue therein, theresident volume will contain undisturbed bone tissue and no void orcavity is formed by the distraction device.

When distraction device 136 is comprised of a substantially rigidthermoplastic material, such as PEEK, the distraction device can bemanufactured by machining a solid block or sheet of thermoplasticmaterial to form the desired shape of the distraction device orelongated member. In other embodiments, the distraction device can beextruded or injection molded. After the distraction device has beenformed from the thermoplastic material, the distraction device can beformed into and constrained in its deployed configuration and heattreated. The heat treatment reduces material stress caused by curving orflexing the distraction device into the deployed configuration. Suchstress reduction reduces the potential risk of fractures or micro-cracksthat may occur in the material of the distraction device as a result offlexing the distraction device. In one embodiment, for example, thedistraction device is heat treated at 160° C. for a period of fiveminutes.

FIG. 6 illustrates distraction device 136 and one embodiment of adelivery system. In this embodiment, distraction device 136 is used inconjunction with a guide member 154, such as a guide wire or deliverytrack. Distraction device 136 includes a center bore or passageway 156(shown in FIG. 5) that accepts guide member 154 for slidably mountingthe distraction device onto the guide member. Prior to deployment,distraction device 136 preferably has a first generally linearpre-deployed configuration, as illustrated in FIG. 6.

Distraction device 136 should have sufficient flexibility to followalong the contour of the guide member 154. For example, distractiondevice 136 may be required to take on a generally linear shape formounting guiding member for deployment into the treatment site and thenmay be required to flex or curve to form a generally coil or springshape within the treatment site.

The guide wire 154 includes a proximal end portion 158 and a distal endportion 160. Distal end portion 160, in a deployed state, preferablydefines a multi-tiered arrangement, scaffolding or platform, such as theillustrated coil or helical shape with a plurality of stacked windings161, as shown in FIG. 6. The shape of distal end portion 160 of theguide member 154 in a deployed state may be predetermined. In oneembodiment, at least the coil shaped distal end portion 160 of the guidemember 154 is made of a shape memory material, such as a Nitinol or apolymer having shape memory characteristics, so that the guide membercan be deformed into a generally straight configuration prior to orduring deployment of the guide member into the treatment site, and thenallowed to reform into its initial coil shape within the treatment site.With this arrangement, the guide member itself may act as an initialdistraction device, contacting the endplates of the vertebra and forcingthem apart. For that purpose, the guide member may also have across-sectional shape (e.g., oval) that tends to reduce contact forcewith endplates or to keep contact force within an acceptable range.

After the coiled distal end portion 160 of the guide wire has attainedthe desired positioned within the treatment site, distraction device 136is advanced along guide member 154 by a pusher 162. As explained in moredetail below, distal end portion 164 of distraction device 136 can betapered, ramped or otherwise configured to facilitate insertion andpassage of the distraction device through the bone and between thetissue layers to be distracted.

A small knob 164 can be mounted at the proximal end portion 158 of theguide member 154 to provide a gripping portion. Knob 164 can be held inplace as pusher 162 is advanced distally along the guide member 154,indicated by arrow D in FIG. 7. Optionally, the pusher can be advancedby a drive mechanism. Advancing the pusher 162 distally forcesdistraction device 136 to advance distally over the guide member 154.Distraction device 136 follows along guide member 154 into betweentissue layers and substantially takes the shape of coiled distal endportion 160 of guide member 154 to form structure 150 having amulti-tiered arrangement or scaffolding. For example, in the illustratedembodiment, distraction device 136 winds into a coil shape as it passesover the coil-shaped distal end portion 160 of the guide member 154.Distraction device 136 winds upon on itself as many times as the numberof windings 161 of the guide member to form a multi-tiered supportstructure or scaffolding, such as the coil or helical shaped structure150.

FIG. 8 illustrates a completed scaffolding or support structure 150 thatis defined by the coiled distraction device 136. The height or extend ofstructure 150 is largely dependent on the height or extend ofdistraction device 136. Top surface 138 and bottom surface 140 ofdistraction device 136 are separated by a first dimension or distance H₁(shown in FIG. 6), which defines the height or extend of the distractiondevice. Structure 150 has a top surface 168 and a bottom surface 170.Top surface 168 and bottom surface 170 are separated by a seconddimension or distance H₂ (shown in FIG. 8), which defines the height orextent of structure 150. The distance H₁ of distraction device 136 isless than the distance H₂ of the structure 150, and the height ofstructure 150 is determined generally by multiplying the number of turnsor windings by the height H₁ of the elongated distraction device. Afterstructure 150 has been formed, if desired, the guide member 154 can beremoved from the deployed distraction device 136. The removal of theguide member 154 can be accomplished by holding the pusher 162 in placewhile pulling the proximal end 158 of the guide member 154 in a proximaldirection. Optionally, depending on the treatment, the guide member 154can remain in place with the distraction device 136 to furtherstrengthen and stabilize the support structure 150. In such usage, theproximal end 158 of the guide member 154 could be severed from theremainder of the guide member by cutting, unscrewing or other means asit is known in the art.

It should therefore be apparent from the above that the presentinvention is particularly advantageous and conducive to minimallyinvasive surgical procedures for treatment of the spine. In accordancewith this aspect of the present invention only a single access openingis required, which may be made transcutaneously and through theappropriate spinal bone or other tissue. Through this single opening arelatively large three-dimensional support structure can be built withinthe confined space of an individual vertebra or between adjoiningvertebrae. Insertion of the distraction device may be aided by anintroduction cannula or sheath, or the distraction device itself may bedirectly advanced through an access opening without the need for acannula or other advancing aid. In any event, in the illustratedembodiment a relatively large support structure is built or formed insitu through a relatively much smaller access opening, providing thebenefits of more drastic and invasive surgical approaches with thesafety and ease of minimally invasive techniques.

FIGS. 9-19 illustrate examples of possible profiles of the distractiondevice and the multi-tiered support structures that can be formed bysuch distraction devices. The various profiles can aid in shaperetention so as to keep the distraction device in the shape of thedeployed support structure and substantially accommodate resistance toboth compressive and lateral forces, among other advantageous features.All of the embodiments in these figures preferably include a channel orpassageway generally designated 172 a-172 i for mounting the distractiondevice onto the guide member. The central channel in some embodimentsalso can be utilized for directing the flow of bone filler or thedelivery of drugs or other fluid materials.

In FIG. 9, the cross-sectional profile is generally square and in FIG.10, the cross-sectional profile is generally rectangular. In both ofthese embodiments, the top surfaces 174 a, 174 b and bottom surfaces 176a, 176 b of the distraction devices are substantially flat surfaces andare in contact when the distraction device is in the deployedconfiguration. The contact between the top and bottom surfaces resultsin a support structure that is very good at resisting compressiveforces. Additionally, as illustrated in FIG. 9 the distraction devicecan have a porous coating 178 throughout or at least on the sides of thedistraction device for better integration into the tissue to be treated.

In FIG. 11, the cross-sectional shape is a custom tongue and grooveprofile having a corrugated shape in which the top surface 174 c and thebottom surface 176 c of the distraction device each include a pluralityof peaks 180 and valleys 182. The peaks 180 and valleys 182 of the topsurface 174 c engage the peaks 180 and valleys 182 of the bottom surface176 c to provide interfering surfaces that add stability and resistslateral slippage.

In FIG. 12, the cross-sectional shape is a custom profile with a singletongue and groove configuration. The distraction device has a groove 184formed in the top surface 174 d of the distraction device and a raisedrib or tongue 186 extending from the bottom surface 176 d of thedistraction device. When the distraction device is curved into thedeployed configuration, tongue 186 extends into groove 184 to provideinterfering surfaces that add stability and resists slippage andshifting due to lateral forces.

In FIG. 13, the cross-sectional shape is a custom profile in which thetop surface 174 e has a convex configuration and bottom surface 176 ehas a concave configuration. When the distraction device forms a supportstructure the concave and convex surfaces 174 e and 176 e engage to addstability and reduce slippage and shifting due to lateral forces.

FIGS. 5 and 14-17 illustrate embodiments of the distraction device thatinclude features which add flexibility to the device and assist indirecting and limiting the direction of flowable bone filler materialinjected into the treatment site. In the illustrated embodiments,materials, such as bone filler or medications, can be injected into anyof the channels 172 f-172 i. The material will flow through the channeland into slots or recesses located in the distraction device. The slotsdirect and/or limit the flow of the material to a specific region withinthe treatment site.

As mentioned above, the illustrated embodiments also include featuresthat aid in the insertion of the distraction device and assist inflexing or curving of the distraction device as it is guided over theguide member. For example, the absence of material between the teeth,i.e., slots, allows the material to bend, thereby enhancing theflexibility of the distraction device and making it easier for thedistraction device to follow the contour of the guide member as theguide member shapes the distraction device into the deployed shape.

FIG. 5 illustrates a distraction device wherein the distraction deviceincludes upward directed slots 146. When bone filler is injected intothe channel 156, the boner filler flows out of the slots 188 and intoareas on both the inside and outside of the distraction device supportstructure.

In FIG. 14, the distraction device includes outwardly facing slots 188a. When bone filler is injected into the channel 172 f, the bone fillerflows out of the slots 188 a into the area outside of the distractiondevice support structure. Thus, the slots 188 a direct the flow of bonefiller toward the outside of the distraction device, and the distractiondevice support structure acts as a barrier, leaving the inner areadefined by the distraction device substantially free of bone fillermaterial.

In FIG. 15, the distraction device includes inwardly facing slots 188 b.When bone filler is injected into the channel 172 g, the bone fillerflows out of the slots 188 b and into the inner space 190 defined by thedistraction device. Thus, the slots 188 b direct and limit the flow ofbone filler toward the inside of the distraction device, and thedistraction device acts like a container that contains the bone fillerwithin the distraction device, leaving the outside region of thedistraction device substantially free of bone filler material.

In FIG. 16, the distraction device has upwardly and downwardly facingslots 188 c, 188 d, which allows bone filler to flow into regions insideand outside of the distraction device.

In FIG. 17, the distraction device has inwardly and outwardly facingslots 188 e, 188 f. In this embodiment, the inwardly and outwardlyfacing slots 188 e, 188 f direct the bone filler toward both the innerspace defined by the distraction device and the region outside of thedistraction device.

The size and dimension of the distraction device when used for thetreatment of vertebral compression fracture is preferably of a size thatcan be inserted through a cannula no larger that about a 6 gauge size(working diameter about 0.173 inches (about 4.39 mm)) which would allowthe distraction device to have a generally square profile of about 0.118inches×0.118 inches (about 3 mm×3 mm). Other sizes and dimensions couldbe used depending on the application. The length of the distractiondevice could be pre-determined or could be cut to fit during thetreatment.

FIGS. 18 and 19 illustrate another embodiment of distraction device 192that comprises a generally elongated member which can be configured toform a distraction device support structure 194. Distraction device 192includes a top portion 193 and a bottom portion 196 connected to eachother by deformable sidewalls 198. The deformable sidewalls 198 includea plurality of connection members 200 spaced along each of thesidewalls. The connection members 200 are biased to hold the top portion193 and bottom portion 196 in a relatively tight configuration.

Referring to FIG. 19, a distraction member 202, such as the illustratedelongated member, can be inserted into and through a passageway 204extending along the center of the distraction device 192. Whendistraction member 202 is inserted into passageway 204, the distractionmember 202 contacts and forces the upper and lower portions 193, 196 ofthe distraction device 192 apart, and the deformable sidewalls 198deform or stretch, i.e., the connection members 200 deform or stretch,to accommodate the separation of the upper and lower portions 193, 196.The separation of the upper and lower portions 193, 196 increases theheight of the distraction device and support structure.

Other devices, systems and methods particularly useful with medicaldevices and procedures described herein are described in U.S. patentapplication Ser. No. ______, Attorney Docket No. 0301-0017.01, entitled“Devices for Treating the Spine” filed on the same day as the presentapplication, which is incorporated herein by reference.

FIGS. 20-24 illustrate one embodiment of the deployment of thedistraction device 136 into a vertebral body 206. Referring to FIG. 20,an introducer sheath or working cannula 208 is introduced through theback of a patient while the patient is lying in a prone position.Fluoroscopic guidance using a biplane imaging system for bettervisualization of the spine may be used to help guide the delivery systemto the desired location. Working cannula 208 can be introduced intovertebral body 206 using a transpedicular access approach. Once workingcannula 208 is inserted through an access port 210 and is in the desiredposition, a delivery cannula 212 is inserted into working cannula 208and the guide member 154 is advanced forward through the deliverycannula 212. Alternatively, the delivery cannula may be inserted intothe vertebra without an introducer sheath.

As explained above, the guide member 154 is preferably made of a shapememory material that has an initial or free state in the shape of a coilor spring. As the guide member 154 is inserted into the delivery cannula212, the cannula constrains the guide member into a generally elongatedlinear configuration, allowing an easy and minimally invasive deploymentof the guide member into the treatment site. Because of the shape memoryproperties, the guide member 154 will return to its coil-shaped freestate once the constraint is removed, i.e., as the guide member exitsthe distal end portion 214 of the delivery cannula 212 and enters thevertebral body 206. The guide member 154 can be advanced throughdelivery cannula 212 manually or with the aid of an advancing mechanism.

As the guide member 154 exits the distal end portion 214 of the deliverycannula 212 and enters the vertebral body 206, the distal end portion160 of the guide member begins to return to its unconstrained shape,i.e., the distal end portion of the guide member begins to wind into itscoil shape. Guide member 154 is advanced and deployed into cancellousbone of the vertebral body 206 until the coil shape reaches the desiredheight or has the desired number of loops or windings 161. As notedearlier, the guide member itself may function to distract or separatethe endplates of a damaged vertebra.

After the guide member 154 has achieved a desired deployedconfiguration, distraction device 136 is advanced over the proximal endportion 158 of the guide member 154 by pusher member 162. As the pushermember 162 is advanced, it contacts the distraction device 136 andadvances it forward or distally over the guide member 154. A drivemechanism can be employed to advance the pusher member 162.

Referring to FIG. 22, as the distraction device 136 is advanced forward(distally) over the guide member 154, the guide member guides thedistraction device through delivery cannula 212 and into vertebral body206. As noted above, the distal end 164 of the distraction device 136can be tapered, ramped or otherwise shaped to aid in passing throughtissue.

In the vertebral body, the distraction device 136 follows along thecoiled shaped distal end portion 160 of the guide member 154 and windsinto a coil shaped support structure 150 as shown in FIGS. 22 and 23.The side slots in the distraction device facilitate curving of thedistraction device so that it follows the contour of the guide member.With each formation of an additional coil or windings 151 of the supportstructure 150, the support structure increases in height. As the supportstructure 150 increases in height, it distracts and supports theendplates of the vertebra, restoring or partially restoring vertebralheight and stabilizing the vertebral body 206. When treating a fracturedvertebral body, the distraction of the endplates stabilizes the fracturebecause the load is no longer applying pressure onto the fracturedsection or onto the fragmented pieces that can pressure the nerveendings surrounding the vertebral body, and thus back pain is reduced.

One advantage of this embodiment of the distraction device, as notedabove, is that it can be inserted through a small access hole and a muchlarger three dimensional support structure, such as a multi-tieredarrangement or scaffolding, can be built within a limited or confinedspace between or within the tissue layers. For instance the distractiondevice 136 can be inserted through a small access hole and the supportstructure 150 can be built one loop at the time by adding one thicknessof the distraction device over another one. As an example, the averagevertebral body is 18 mm in height. As illustrated in FIG. 2, after avertebral body compression fracture, the vertebral body can be abouthalf of the height of a normal vertebral body, which would result in acompressed body of about 9 mm. By way of example, a guide wire in theform a wire with a 1 mm in diameter with a pitch about half of the wiresize would require about 5 loops to span from endplate to endplate. Whenthe distraction device is inserted onto the guide member, it will startwinding along the loops and distract or push up and down in the axialdirection which may benefit from the mechanical advantage of advancingover a coil. Because the fractured body has less resistance, it willexpand the distance between the two endplates until they are preferablyat the pre-fractured position, as illustrated in FIG. 24.

After the distraction device 136 has been deployed, the guide member 154can be retracted from the distraction device and removed from thesystem. This can be accomplished by holding the pusher member 162 inplace while retracting the guide member 154 in a proximal direction. Forexample, the guide member 154 can be retracted proximally by reversingthe advancing mechanism.

FIGS. 25-29 illustrate one method of deploying a distraction device 136over a guide member 154 wherein the distraction device and the guidemember are deployed incrementally. The incremental method describedherein can be used to deploy the distraction device into tissue orbetween tissue layers at any desired location within the body and isparticularly useful in treating spinal tissue, such as vertebrae andintervertebral disks.

Referring to FIG. 25, a portion 216 of the guide member 154 is advancedout of the distal end portion 218 of a cannula 220 and into a treatmentsite. Next, the distraction device 136 is advanced over the portion 216of the guide member 154 (FIG. 26). The guide member 136 is then furtheradvanced out of the cannula 220 (FIG. 27) to extend portion 216 of theguide member 154 past the distal end portion 164 of the distractiondevice 136, and the distraction device 136 is then further advanced overthe guide member 154 (FIG. 28). The incremental deployment of the guidemember 154 and distraction device 136 continues until the supportstructure 150 attains the desired height (FIG. 29).

One of the benefits of incremental deployment is that the distractiondevice aids in maintaining the shape of the guide member as the guidemember is deployed. For example, the distraction device supports theguide member and aids in preventing radial dilation of the guide member.Another benefit is that the distraction device provides a path for theguide member, which reduces the amount of friction between the guidemember and the tissue in which it is inserted.

During deployment of the guide member and the distraction device, it isadvantageous to have the ability to control the placement andorientation of the guide member and spinal implant within the treatmentsite. For example, if the guide member and distraction device aredeployed at an undesired trajectory or orientation, the surgeon mustretract the guide wire and/or the distraction device, reorient thedeployment system and redeploy the guide member and/or the distractiondevice. Additionally, when the guide member is being deployed at alocation that is surrounded by sensitive tissue, such as nerves andblood vessels, it is highly advantageous to be able to predict andcontrol the trajectory and/or orientation of the guide member duringdeployment.

FIGS. 33-42 illustrate various embodiments of the distal end portion ofthe delivery cannula that include features and elements for controllingthe trajectory and orientation of the guide member during deployment.Referring to FIGS. 33 and 34, delivery cannula 222 includes an end wall224 and a sidewall 226. Sidewall 226 includes an opening 228therethrough, which communicates with the internal passageway of cannula222. Opening 228 is defined by proximal edge 230, a distal edge 232 andtop and bottom edges 234, 236. The proximal edge 230 includes a recessor “keyhole” 238 that is configured to accept and mate with guide member154 as it is advanced out of window 228. Referring to FIG. 34, as guidemember 154 is advanced out of opening 228, the guide member engagesrecess 238, which constrains and controls guide member's location withinopening 228, thus controlling its trajectory.

Optionally, sidewall 226 also can include a guide channel or “keyway”240 that orientates guide member 154 within the internal passageway ofthe cannula 222 and guides the guide member 154 toward recess 238 as theguide member is advanced through the cannula 222. Furthermore, in theevent that the proximal end portion 160 of guide member 154 is requiredto be retracted into cannula 222 so that the distal end portion 160 ofguide member 154 is below-flush relative to proximal edge 230 orcompletely retracted into cannula, distal end portion 160 of guidemember 154 will remain in contact with guide channel 240, thus, keepingthe guide member aligned with recess 238. When guide member 154 is onceagain advance toward and out of window 228, guide channel 240 willdirect the guide member 154 toward recess 238, thus ensuring that guidemember 154 will exit out of window 228 at the desired location.

In one embodiment, sidewall 226 includes cut outs 242, 244 located oneither side of proximal edge 230 of window 228. Cut outs 242, 244 allowa portion of the sidewall or flap 246, adjacent proximal edge 230, todefect outwardly along line 248 of FIG. 33, as distraction device 136 isdeployed through opening 228, as shown in FIG. 36. Flap 246 provides abearing surface for distraction device 136 to ride against, whichreduces friction, and thus reduces the drive force required to deploythe distraction device. In one embodiment, the material of sidewall 226has sufficient strength so that flap 246 does not deflect outwardlyunder the force applied to it during the deployment of guide member 136(as shown in FIG. 34), but has sufficient flexibility so that flap 246deflects outwardly under the force applied to it during the deploymentof distraction device 136 (as shown in FIG. 36). Referring to FIG. 35,to assist the deflection flap 246, sidewall 226 can include stressrelief holes 250 that allow the material to more easily bend or flexalong line 251 as the distraction device is deployed.

It will be understood that the distal end portion of the cannula caninclude any of these features, i.e., the keyhole, keyway, and flap,individually or in any combination.

FIG. 37 illustrates another embodiment of a distal end portion 252 of adeployment cannula 254. Deployment cannula 254 includes an opening 256in the sidewall 258 of the cannula. In this embodiment, cannula 254includes a curved internal wall 260 located within the internalpassageway of cannula 254. Curved internal wall 260 is sloped so thatwhen the guide member and the distraction device are advanced throughthe internal passageway of cannula 254, the distal end portions of theguide member and the distraction device will contact curved internalwall 260 and be directed toward opening 256. In other words, the slopeof the curved internal wall 260 guides the advancing guide member anddistraction device toward opening 256, providing a smooth transition andexit of such members out of opening 256.

Also, as illustrated in FIGS. 37 and 37A, a portion 262 of the sidewall258 can be curved so that it protrudes into internal passageway 264 ofcannula 254 to provide a guide element within the cannula that orientsand maintains the alignment of the distraction device 136 withindeployment cannula 254. Referring to FIG. 37A, as distraction device 136is advanced through internal passageway 264 of deployment cannula 254,protruding portion 262 of sidewall 258 engages a recess or groove 268 inone of the surfaces of distraction device 136. This engagement alignsdistraction device 136 within deployment cannula 254 and maintains theorientation of the distraction device within the deployment cannula asthe distraction device is advanced therethrough.

FIG. 38 illustrates one embodiment of a working cannula 270 that can beused in conjunction with a deployment cannula to deploy a guide memberand a distraction device between tissue layers. Working cannula 270includes a sidewall 272 and an end wall 274. Working cannula 270 alsoincludes an opening 276 in sidewall 272 that communicates with internalpassageway of working cannula 270. Opening 276 varies in size andincludes a wide portion 278 and a narrow portion 280.

Referring to FIG. 39, in use, a deployment cannula 282, which may be anyof the deployment cannulas described above, is inserted into theinternal passageway of working cannula 270 so that opening 284 ofdeployment cannula 282 is aligned with opening 276 of working cannula270, collectively defining a deployment window 286. As indicated byarrows 288 and 290 working cannula 270 and deployment cannula 282 arerotatable relative to one another. As used herein “relative rotation” isintended to include the situation in which one of the cannulas isrotated relative to the other cannula, i.e., one cannula is held inplace while the other is rotated, and the situation where both cannulasare rotated simultaneously. As will be explained in more detail below,the size of window 286 can be adjusted by rotating the cannulas relativeto one another.

Referring to FIG. 40, deployment cannula 282 and working cannula 270 arerotated relative to one another so that narrow portion 280 of opening276 of working cannula 270 is aligned or located over opening 284 ofdeployment cannula 282. Narrow portion 280 of opening 276 of workingcannula 270 is smaller in size than opening 284 of deployment cannula282, which results in a relatively small deployment window 286 that islarge enough to allow deployment of the guide member 154, but smallenough to prevent deployment of the distraction device. One advantage ofsuch a configuration is it that is prevents inadvertent or prematuredeployment of the distraction device because the relatively small sizeof deployment window 286 prevents such deployment. When deploymentwindow 286 is in such a configuration, guide member 154 is advancedthrough deployment cannula 282 and deployed out of deployment window286. In one embodiment, the dimensions of deployment window 286 in therelatively smaller configuration are slightly larger than the dimensionsof guide member 154, so that window 286 constrains guide member 154 andcontrol its orientation and trajectory as it exits the window.

After a desired amount of guide member 154 has been deployed, workingcannula 270 and deployment cannula 282 are again rotated relative to oneanother to adjust the dimensions of the deployment window 286.Specifically, the cannulas are rotated so that the wide portion 278 ofopening 276 of working cannula 270 is aligned with opening 284 ofdeployment cannula 282, as illustrated in FIG. 41. Wide portion 278 ofopening 276 of working cannula 270 preferably is the same size as orlarger than opening 284 of deployment cannula 282, and in any event islarge enough to allow the advancement of distraction device 136 throughthe window 286. Referring to FIG. 42, after window 286 has been adjustedto the larger configuration, distraction device 136 is advance alongguide member 154, through deployment cannula 282 and out of window 286.

As discussed above, the distraction device of the disclosure ispreferably but not exclusively used with flowable material, such ascurable bone filler material, to add stability to the distraction deviceand support structure between the distracted tissue, i.e., the endplatesof the vertebra. Flowable filler material can be introduced into thetreatment site using a variety of different methods and techniques. Forexample, bone filler material can be introduced by the methods andtechniques described in co-owned U.S. patent application Ser. No.11/464,782, filed Aug. 15, 2006, which has been incorporated byreference above, and U.S. Provisional patent application Ser. No.______, Attorney Docket No. 0301-0023, entitled “Methods ofInterdigitating Flowable Material with Bone Tissue” filed on the sameday as the present application, which is herein incorporated byreference.

FIGS. 30-32 illustrate another embodiment a device and method forinjecting flowable material into the treatment site and methods of usethereof. FIG. 30 illustrates a flowable material injection device 300.Device 300 includes a supply of flowable material 302, such as a syringecontaining flowable material 304, and a flowable material delivery tubeor needle 306. Delivery tube 306 has a proximal end portion 308, adistal end portion 310 and a fluid passageway therebetween. Proximal endportion 308 is configured to be operatively connected to and receiveflowable material from flowable material supply 302.

Distal end portion 310 includes an opening 312 for delivering flowablematerial into a treatment site. Distal end portion 310 preferably iscomprised of a shape memory material, such as Nitinol or other shapememory alloy, and in its initial or free-state configuration, distal endportion 310 has a curved portion 314, which permits directional deliveryof the flowable material from opening 312. Additionally, distal endportion 310 can be constrained in a generally linear or straightconfiguration, as illustrated in FIG. 31. For example, in use, deliverytube 306 can be inserted into a cannula, such as a working cannula, toaccess a treatment site. When delivery tube 306 is inserted into theworking cannula, distal end portion 310 of the delivery tube isconstrained in the generally linear configuration, shown in FIG. 31, forpassage through the cannula. When distal end portion 310 of deliverytube 306 exits out of the cannula, the distal end portion returns to itscurved configuration to permit directional deployment of flowablematerial.

FIG. 32 illustrates one method of employing delivery device 300 todeliver flowable material 304 into a resident volume 316 defined by adistraction device 318. In FIG. 32, distraction device 318 has beendeployed into a vertebral body 320 in accordance with any of the methodsdescribed above. After distraction device 318 has been deployed, theworking cannula 322 is positioned within vertebral body 320 so thatdistal end opening 324 of working cannula 322 is located adjacentresident volume 316 of distraction device 318. Delivery tube 306 isinserted into working cannula 322 and distal end portion 310 of thedelivery tube is constrained in the generally linear configuration as itis advanced through the working cannula. When distal end portion 310 ofdelivery tube 306 exits opening 324 of working cannula 322, theconstraining force is removed from distal end portion 310 of deliverytube 306 and the delivery tube returns to its original curvedconfiguration. Preferably, the delivery tube 306 curves so that opening312 in distal end portion 310 of the delivery tube is located in ororiented toward resident volume 316. Once distal end portion 310 ofdelivery tube 306 is in the desired location, flowable material 304 isinjected into delivery tube 306 from fluid supply 302 and deliveredthrough delivery tube 306 into resident volume 316. If cancellous bonematerial is located within the resident volume, the flowable materialinterdigitates with the cancellous bone tissue.

FIG. 90 illustrates another embodiment of injecting flowable materialinto a vertebral body. In this embodiment flowable material 304 isinjected on the superior side 326 of distraction device supportstructure 318, the inferior side 328 of distraction device supportstructure 318 or on both sides 326, 328. For example, in the illustratedembodiment, a vertebra 330 has a distraction device support structure318 deployed therein, and flowable material 304 is injected only on thesuperior side 326 of support structure 318. The flowable material 304can cover the superior side 326 of support structure 318 to create acap-like structure that fills any portions of the cancellous bonebetween the superior side 326 of the support structure 318 and thesuperior vertebral endplate 332. The flowable material 304 can beinjected by any method know in the art or by any of the methodspreviously described in the above referenced co-owned patentapplications.

In a further embodiment, the flowable material can be injected into aselected number of loops or windings of the distraction device supportstructure. For example, after the distraction device has been deployedto form the distraction device support structure, cement could beinjected into the resident volume of the support structure so that aportion of the resident volume defined by a selected number of loops isfilled with cement and a portion of the resident volume defined by therest of the windings remains unfilled by cement. Filling only a portionof the resident volume of the distraction device support structureresults in a distraction device support structure having portions ofvarying levels of flexibility and stiffness.

FIGS. 107-112 illustrate an optional compressible feature of thedistraction device. As explained above, the distraction device ispreferably made of a substantially rigid biocompatible material, such asa substantially rigid thermoplastic material, for example PEEK. Becauseof the natural characteristics of such materials, the distraction deviceis substantially rigid or incompressible in the dimension or directionbetween the top surface and the bottom surface of the distractiondevice. As used herein the terms “substantially rigid” and“substantially incompressible” are intended to mean that the materialand the device do not substantially deflect under loading. The rigidityof the distraction device in this dimension results in the creation of asubstantially rigid or incompressible support structure formed by thedistraction device. While a substantially rigid support structure ishighly advantageous in many applications, there are some applicationswhere having an elastically compressible support structure has someadvantages. As used herein the term “elastically compressible” isintended to mean that the device compresses or substantially deflectswhen loading is applied to the device, and the device elasticallyreturns to a less compressed state as the load is reduced and/orsubstantially returns to its original uncompressed state when the loadis removed.

FIG. 107 is an exemplary embodiment of a cross-sectional view of any ofthe distraction devices described herein. For example, FIG. 107 can be across-sectional view of the distraction device shown in FIG. 10 andtaken along line 107-107. The distraction device 334 preferablycomprises a substantially rigid thermoplastic material, such as PEEK,and includes stress relief chambers 336 located on either side of acenter passageway 338. The stress relief chambers can be lumens thatextend along the length of the distraction device or honeycombs or voidsthat are spaced along the distraction device. Additionally, although theillustrated embodiment only shows two chambers 336, there can be anynumber of chambers contained within the device.

As illustrated in FIG. 108, when a load or force F is applied to the topand bottom surfaces 340, 342 of distraction device 334, stress reliefchambers 336 translate the force to the sidewalls 346, 348. Becausethere is no material, i.e. voids, between the sidewalls 346, 348 and thecenter wall 350, the sidewalls and center wall are allowed to bow offlex, which results in an elastic compression of distraction device 334in the dimension or direction between the top and bottom surface 340,342. As the load or compression forces are reduced, distraction device334 elastically returns to a less compressed state, or in the situationwherein the load is completely removed, distraction device 334elastically substantially returns to its original uncompressed state.

The amount of compression that the distraction device 334 will exhibitand the load under which the distraction device will substantiallydeflect or elastically compress largely depends on the size andconfiguration of stress relief chambers 336. In one embodiment,distraction device 334 is configured to substantially elasticallycompress under normal physiological loading endured by tissue of thehuman spine, and be substantially rigid or does not exhibit substantialdeflection under loads less than those normally endured by tissue of thehuman spine.

For example, the normal range of physiological loading that tissue ofthe human spine endures is about 300 Newtons (N) to about 1000 N. In oneembodiment, the stress relief chambers 336 are configured so thatdistraction device 334 is substantially incompressible or does notexhibit substantial deflection when it is place under a loading of lessthen 300 N, but is elastically compressible or exhibits a substantialdeflection when it is place under a loading of about 300 N or greater.In another embodiment, distraction device 334 is substantiallyincompressible or remains rigid under a loading of less then 300 N andis substantially elastically compressible under a loading between about300N to about 1000 N.

Compressible distraction device 334 can be used to treat damagedvertebral bodies and can also be used in nucleus replacement and fusionprocedures to treat intervertebral disks. FIGS. 109-112 illustrate onemethod of treating an intervertebral disk with a compressibledistraction device.

FIG. 109 is a top view of an intervertebral disk 352 in which thenucleus material has been removed the disk, using standard techniquesand procedures know in the art, leaving a nuclear space 354 withinannulus 356. A guide member 358, such as any of guide members disclosedherein, is deployed into nuclear space 354 and compressible distractiondevice 334 having the elastically compressible feature is deployed overguide member 358 to form a support structure 360 within nuclear space354, as illustrated in FIG. 110. Because nucleus disk space 354 isrelatively small, the support structure includes about two or threeloops or windings 361, as illustrated in FIGS. 111 and 112. However, thesupport structure can include more or less windings depending on thesize of the distraction device and the size of the nucleus disk space.

After support structure 360 has been formed, guide member 358 is removedleaving the support structure in the nuclear space 354. Referring toFIGS. 111 and 112, when deployed within nuclear space 354, the topsurface 362 of the support structure 360 contacts and supports theinferior endplate 364 of the superior vertebra 366, and the bottomsurface 368 of the support structure 360 contacts and supports thesuperior endplate 370 of the inferior vertebra 372. As the spinal columnmoves during normal activities, the endplates 364, 370 apply loading tosupport structure 360. Comparing FIGS. 111 and 112, FIG. 112 illustratessupport structure 360 under an at-rest loading of about 300 N or less,wherein support structure 360 has very little or no compression, i.e.,does not exhibit substantial deflection. In contrast, FIG. 111illustrates support structure 360 under a loading of greater than about300 N. Under this loading, support structure 360 substantially deflectsor yields to the force and elastically compresses. Additionally, asexemplified by FIG. 111, when there is uneven loading between theposterior side 374 and anterior side 376 of the spinal column, i.e., theposterior side 374 of the spinal column applies a greater loading thanthe anterior side 376, the posterior side 378 and anterior side 380 ofsupport structure 360 can elastically compress in different amounts toaccommodate such uneven loading.

As explained above, when the loading is remove or returns to the loadingof an at rest state, support structure 360 returns to the lesscompressed state as shown if FIG. 112. Additionally, the above describeddistraction device can be used in a fusion procedure in which bone graftmaterial can be inserted in and around the distraction device.

Depending on the procedure, sometimes it is necessary for thedistraction device to channel or bore through tissue, such as cancellousbone. For such applications, the distal end portion of the distractioncan be configured to reduce the amount of penetration force required forinsertion of the distraction device. For example, the distal end portioncan be designed to reduce the amount of friction between the tissue andthe distraction device, or the distal end portion can be designed toweaken the structural integrity of the tissue by breaking or cuttingthrough the tissue.

FIGS. 43-64 illustrate several different embodiments of distal endportions of distraction devices. FIG. 43 illustrates a distractiondevice 382 mounted on a guide member 384 where the distal end portion386 of distraction device 382 includes a taper. The tapered distal endportion 386 minimizes the surface area of the frontal face 389 ofdistraction device 382 to reduce the bluntness of the frontal face andto provide a generally pointed distal end portion 386 that is moreconducive to piercing tissue.

FIG. 44 illustrates a distal end portion 388 that includes a firsttapered section 390 followed by a thin walled section 392 locatedproximal the first tapered section. The thin walled section 392 has across-sectional width or diameter that is generally smaller than that ofthe proximal end portion 394 of the distraction device. The thin walledsection 392 provides flexibility to the distal end portion and arelatively longer tissue penetrating portion. The distal portion 388also can include a second tapered section 396 proximal the thin walledsection 394. The second tapered section 396 provides an angled surfaceleading to the proximal portion 394 of the distraction device.

FIG. 45 illustrates a distal end portion 398 of a distraction device 400that can be generally described as a flared nose. The distal end portion398 includes a tapered section 402 that leads into a section 404 whichhas a diameter or cross-sectional width that is larger than the majorityof the proximal portion 406 of distraction device 400. The flared nosecreates a pathway that is larger than the remaining portion of thedistraction device, which reduces drag as the proximal portion 406 ofthe device is inserted through tissue.

FIG. 46 illustrates a distal end portion 408 that is comprised of amaterial that is more rigid than the proximal end portion 410 ofdistraction device 412. In one embodiment, distal end portion 408 iscomprised of a metal, such as stainless steel, titanium, platinum or anyother suitable metal or metal alloy. The distal end portion 408 can alsobe comprised of any other suitable material that is more rigid than theproximal end portion 410 of distraction device 412, such as a rigidplastic or polymer. Optionally, the distal end portion 408 can include aradiopaque marker.

FIGS. 47-64 illustrate distal end portions of a distraction device thatreduce the amount of penetrating force required to insert thedistraction device into tissue by providing features that are adaptedfor cutting or breaking through tissue. For example, FIG. 47 illustratesa distal end portion 414 that has a tapered section adapted for piercingand breaking through tissue.

FIG. 48 illustrates a distal end portion 416 of a distraction device 418that has a flat chisel or duckbill edge 420 that extends horizontallyacross the front face of the device.

FIG. 49 illustrates a distal end portion 422 of a distraction device 424that has a vertical chisel or duckbill edge 426 that extends verticallyacross the front face of the distraction device.

FIG. 50 illustrates a distal end portion 428 that has a star shapedconfiguration which includes multiple cutting edges 430.

FIGS. 51 and 52, illustrate a distraction device 432 including a distalend portion 434 having a tapered polygonal shape with multiple cuttingedges 436. Distraction device 432 also includes a top surface 438 thathas a groove 439 extending along the distraction device, and a bottomsurface 440 that includes a protruding portion 441 extending therefrom.When the distraction device is formed into the support structure, theprotruding portion 441 mates with or seats within the groove 439 to givethe structure strength and integrity to the support structure.

FIGS. 53, 54 and 56 illustrate distal end portions of a distractiondevice that have multi-faced cutting surfaces. For example, FIGS. 53 and54 illustrate a distal end portion 442 that have three cutting faces444, and FIG. 56 illustrates an embodiment that has four concave faces446.

FIGS. 55 and 57 illustrate a distal end portion 448 of a distractiondevice that has multiple cutting faces and edges in a complexconfiguration.

FIGS. 58 and 59 illustrates a distal end portion 450 of a distractiondevice that has multiple cutting faces and edges in a cross-shapedconfiguration.

FIGS. 60 and 61 illustrate a distal end portion 452 of a distractiondevice 454 that has a chiseled cutting edge 456 including a notch orgroove 458. The notch 458 is configured to correspond to the shape andsize of the guide member so that the distal end portion 452 of thedistraction device nests against the guide member as the distractiondevice is advanced along a guide member and into tissue. Because thenotch 458 nests against the guide member, the distal end portion 452does not need to be as flexible as it follows along the guide member.Additionally, the notch 458 allows the longer distal end portion 452 tofollow along the guide member without bending or flexing. Accordingly,the distal end portion 452 can be made of a longer, more rigid materialthat provides added stiffness for inserting the distal end portion intotissue.

Additionally, as illustrated in FIG. 62, the passageway 460 ofdistraction device 454 can be configured or keyed to the shape of theguide member 462. In the illustrated embodiment, the guide member has asquare cross-sectional shape and the passageway 460 includes flatsurfaces 464 that mate with surfaces 466 of guide member 462. The keyingof the distraction device 454 to the guide wire ensures properorientation of distraction device 454 and prevents the distractiondevice from rotating about guide member 462. Prevention of distractiondevice rotation about the guide member reduces the amount of insertionforce lost to such rotation, thus providing a greater insertion forcefor passage through tissue.

FIGS. 63 and 64 illustrate a distraction device 468 that includes adistal end portion 470, which is tapered to point and includes a surfacethat has serrated edges 472. The serrated edges cut and break tissue asthe distraction 468 is inserted into the tissue.

The distraction devices of the present invention can also includesurfaces that frictionally or mechanically engage each other during andafter the formation of the distraction device support structure. Thefrictionally engaging surfaces can provide several benefits, such aseliminating or reducing movement between adjacent windings of thesupport structure, providing better rotational movement and transmissionof torque during deployment and preventing unwinding or dilation of thewindings under axial loading.

FIG. 65 illustrates one embodiment of a distraction device 474 that hasfrictionally engaging surface. The distraction device 474 includes topwall 476 and a bottom wall 478 both of which include a textured surface480 at least partially extending along the distraction device. Thetextured surfaces of the top wall 476 and the bottom wall 478 arepreferably configured to fictionally engage and interlock with eachother when the distraction device is configured to define thedistraction device support structure.

In the illustrated embodiment, the top wall 476 and the bottom wall 478include knurls 482 that extend perpendicular to the axis X of thedistraction device 474 when the distraction device is in a generallylinear configuration. The knurls 482 can be similar to the knurlscommonly found on plastic poker chips. However, it will be understoodthat the top and bottom surfaces could have a variety of differentlyconfigured frictionally engaging surfaces without departing from thepresent invention.

Referring to FIG. 66, as the distraction device 478 is wound to form thedistraction device support structure 484, by the use of a guide memberor other method, the knurls 482 on the top and bottom walls 476, 480 ofthe distraction device 474 frictionally or mechanically engage eachother to interlock adjacent windings 486 together. During deployment ofthe distraction device 474 and while forming the support structure 484,the knurls 482 can function as a gear-like system that allows the forceapplied to the proximal end of the distraction device 478 to beefficiently translated to the distal end of the distraction device.Furthermore, during deployment, the distraction device 474 rotates as asingle cylindrical unit rather than multiple independent windings.

Additionally, after the distraction device 474 has been implanted andthe distraction device support structure 484 has been formed, theinterlocking of the adjacent windings 486 reduced the amount ofunwinding or radial dilation that can be caused by axial loading. Forexample, if the adjacent windings 486 are not interlocked, loading orforce in the axial direction can cause the top and bottom ends of thedistraction device support structure to dilate or unwind. The engagementbetween the knurls 482 of the top and bottom walls 476, 478 interlockthe adjacent windings, which assists in reducing such dilation.

FIG. 67 illustrates another embodiment of a distraction device 488 thathas surfaces that interlock as the distraction device forms the supportstructure 490. In this embodiment, the distraction device 488 has agenerally wavy configuration wherein the distraction device includespeaks 492 and valleys 494 that are spaced apart by a pitch “P”. As thedistraction device 488 is deployed and winds or coils to form thesupport structure 490, the peaks 492 of one winding 496 align with andengage the valleys 494 a of an adjacent winding 496 a and the valleys494 of the winding 494 align with and engage the peaks 492 a of theadjacent windings 496 a. During deployment, the mating of the adjacentpeaks and valleys can function as a self-locating or self-aligningfeature which assists in properly aligning each winding with theadjacent winding. Additionally, the wavy-shaped distraction devicepreferably has a rounded or smooth peaks and valleys that reducefriction as the distraction device is inserted into tissue.

In addition to the wavy construction, the distraction device 488 has agenerally V-shaped or chevron shaped cross-section that has a groove 498in the top wall and a protruding portion 500 bottom wall that mate whenthe distraction device 488 is formed into support structure 490. Themating of the groove 498 and protrusion 500 of the chevron shapeddistraction device 488 assists stabilizing the distraction devicesupport structure.

FIGS. 68 and 69 illustrate one embodiment of a distraction device 502that is configured to provide interlocking windings or tiers 504 whenthe distraction device forms the distraction device support structure506. The distraction device 502 includes a top wall 508 and a bottomwall 510. The top wall 508 includes a plurality of protrusions 512 thatextend from the top wall and are spaced along the distraction device.The bottom wall 510 includes a plurality of recesses 514 that areconfigured to accept the protrusions 512 when the distraction device 502is configured to form the support structure 506.

When the distraction device 502 is wound or configured to form thedistraction device support structure 506, the protrusions 512 initiallyenter the slots 516 between the teeth 518. As the distraction device 502continues to wind, the protrusions 512 move further into the slots 316and eventually into the recesses 514 located in the bottom wall 510 ofthe distraction device 502 to interlock the adjacent windings 504 asillustrated in FIG. 69.

The protrusions 512 and the recesses 514 can have a variety ofconfigurations. For example, FIG. 70 illustrates a protrusion 512 ashaped like a cylindrical peg. FIG. 71 illustrates a protrusion 512 bhaving one angled surface, and FIG. 72 illustrates a protrusion 512 chaving two angled surfaces.

Referring to FIGS. 73-75, in an alternative embodiment of thedistraction device 520, the protrusions 522 can extent from the bottomwall 524 and the recesses 526 can be located in the top wall 528 and inpart of the back wall 530. As the distraction device 520 is wound toform the distraction device support structure 532, the protrusions 522engage the recesses 526 and interlock the adjacent windings 534 (FIG.74). Optionally, the protrusions 522 and the portions of the distractiondevices between the recesses 526 could include a hole 536 (FIG. 75)extending therethrough and for receiving a retaining member. When theprotrusions 522 engage the recesses 526, the holes 536 align to form apassageway in which a retaining member, such as a wire, can be insertedthrough the holes 536 to secure the adjacent windings 534 together andprove added stability to the support structure 532.

FIGS. 76-83 c illustrate further embodiments of the distraction devicewherein the distraction device includes hinged tabs that are movablebetween a first unlocked position and a second, locked position.

Referring to FIGS. 76 and 77 distraction device 540 includes movabletabs 542. Tabs 542 include a locking member 544, an activation member546 and a hinge member 548, such as a pin, therebetween. As will beexplained in greater detail below, the tab rotates about the hingebetween an unlocked and a locked position. As shown in FIG. 77, when tab542 is in the unlocked position, the locking member 544 is situated in arecess located in the top surface 550 of the distraction device 540, sothat locking member 544 is level or below level with top surface 550 ofdistraction member 540. During deployment of the distraction device overa guide member 552, the guide member is located with passage 554 (shownin FIGS. 76 and 78) and in contact with the activation member 548,keeping tab 542 in the locked position. After the windings have beenstacked one on top of the other to form the support structure, guidemember 552 is removed from central passage 554 of the distraction device540 and out of contact with activation member 548. Referring to FIG. 78,after guide member 552 has been removed from passageway 554, theactivation member 548 moves into the passageway, and the tab 542 rotatesabout hinge 546 to move the tab into the locked position. Tabs 542 arebiased to the locked position, by for example, weighting the tabs oremploying a leaf spring, so that the tabs move to the locked positionwhen the guide member is removed.

In the locked position, the locking member 544 extends above top surface550 of distraction device 540 and is in locking engagement with a recessor pocket 556 (shown in FIGS. 76 and 77) located in the bottom surface558 of the distraction device 540, thereby securing the adjacentwindings and providing added support and integrity to the supportstructure.

In the embodiments illustrated in FIGS. 79 and 80, tab 560 is located inthe bottom surface 562 of the distraction device and recess orengagement pocket 564 is located in the top surface 566 of thedistraction device. Similar to the embodiment above, when the guidemember 552 is located within the passageway 554, the guide membercontacts the activation member 568 to bias the tab 560 to the unlockedposition. After the structure has been formed, the guide member 552 isremoved and the locking member 570 of tab 560 extends from the bottomsurface 562 and engages the recess 564 located in the top surface 566.

The embodiments illustrated in FIGS. 81 and 82 are similar to thosedescribed above except that the locking tab 572 is located in a wall 574that defines a groove 576 in the top surface 578 and the recesses orengagement pocket 580 is located in a wall 582 defining a projection 584of the bottom wall 586 that mates with groove when the distractiondevice is formed into the support structure.

The embodiments of FIGS. 83A-83C are similar to those described aboveexcept that the locking tabs 588 and recesses 592 extend in a directionthat is parallel with the longitudinal axis of the distraction device590, as shown in FIG. 83B. When guide member 552 is located with in thecentral passageway of distraction device 590, guide member 552 contactsactivation member 593, biasing tab 588 in the unlocked position.Referring to FIG. 83C, when guide member 552 is removed from thepassageway and out of contact will activation member 593, tab 588rotates so that locking element 595 is received into and engages recess592, thereby interlocking the adjacent windings.

FIGS. 84-87 illustrate further embodiments of the distraction device. Inthese embodiments, the distraction devices include interlockingprojections or teeth that interlock to provide stability to the supportstructure.

Referring to FIG. 84, similar to the above described embodiments,distraction device 594 includes alternating projections or teeth 596 andintervening slots or recesses 598. The projections 596 include aproximal wall portion 599 and a distal wall portion 600. In thisembodiment, the proximal wall portions 599 of projections 596 include adownwardly extending friction fit element 602 and the distal wallportions 600 of projections 596 include an upwardly extending frictionfit element 604. Referring to FIG. 85, when distraction device 594 iscurved to from a support structure, the downwardly extending frictionfit elements 602 of the proximal wall portions 599 frictionally engagethe upwardly extending friction fit elements 604 of the adjacent distalwall portions 600 to interlock the projections together. For example,the downwardly extending friction fit element 602 extending fromproximal wall portion 599 a of projection 596 a frictionally engages theupwardly extending friction fit element 604 extending from distal wallportion 600 b of projection 596 b, thereby securing projection 596 a to596 b to provide structural support to the support structure andprevents dilation of the support structure when it is exposed to axialforces.

FIGS. 86 and 87 illustrate another embodiment of a distraction device606. In this embodiment, the distal wall portions 608 of the projections610 include a protruding friction fit element 612, and the proximal wallportions 614 include recesses 616 for receiving and frictionallyengaging the friction fit elements 612. In one embodiment, theprotruding friction fit elements 612 and the recesses 616 each have agenerally T-shaped configuration. In another embodiment, the distal wallportion 608 includes multiple protruding friction fit elements 611 andthe proximal wall portion 614 includes multiple recesses 617. It shouldbe understood that the protruding friction fit elements and the recesscould be located on either the proximal wall portion or the distal wallportion.

Referring to FIG. 87, when distraction device 606 is curved to form asupport structure, the protruding friction fit elements 612 of distalwall portions 608 are received into and frictionally engage the recesses616 of the adjacent distal wall portions 614 to interlock theprojections together. For example, the protruding friction fit element612 a extending from distal wall portion 608 a of projection 610 a isreceived into and frictionally engages recess 616 b of proximal wallportion 614 b of projection 610 b, thereby securing projection 610 a toprojection 610 b to provide structural support to the support structure.

FIG. 87A illustrates another embodiment of a distraction device 615. Inthis embodiment, the distraction device includes a reinforcing orretaining member 623 (shown in phantom) extending through the centralpassageway 619 of the device. The reinforcing member is configured intothe shape of the support structure 621 and assists in maintaining theshape of the support structure. The reinforcing member can be a wire ora ribbon made from a metal or metal alloy, such as steel or Nitinol, ora polymer material. Additionally, the reinforcing member can be insertedinto the passage 619 of the distraction device 615 after the distractiondevice has been formed into the support structure 621 and the guidemember has been removed.

Alternatively, the reinforcing member can be a tube, such as a metalhypotube, that is inserted into and attached to the central passageway619 of distraction device 616 prior to deployment over the guide member.In this instance, the guide member would be received into the tubularreinforcing member, which is located in passageway 616, and the tubularreinforcing member and distraction device are jointly deployed over theguide member.

FIGS. 88 and 89 illustrate a distraction device 620 that includes atleast one anchor 622 extending from the back wall or spine 624 of thedistraction device, such as the illustrated thread-like projection. Theanchor 622 can be one continuous elongated projection extending thelength of the distraction device, or the anchor 622 can be a pluralityof individual projections spaced apart along the back wall 624. Asillustrated in FIG. 89, when the distraction device 620 is implantedinto tissue, such as cancellous bone 626 of a vertebra 628, and is woundto form the distraction device support structure 630, the anchor 622imbeds into the cancellous bone 626 surrounding the support structure630. When a compressive load is placed on the support structure 630 inthe axial direction, the anchor 622 bears a portion of the load, whichaids in the support structure maintaining its position within thetissue.

As discussed above, the distraction device can include teeth and slotsthat assist in adding flexibility to the distraction device. The teethand slots of the distraction device can be configured to includefeatures that, among other things, reduce friction as the distractiondevice is inserted into tissue, increase the compressive strength of thesupport structure in the axial direction and prevent radial dilation.

In FIGS. 91 and 92, the distraction device 632 includes teeth 634 thatextend at an angle from the back wall or spine 636 of the distractiondevice. The teeth 634 are preferably angled at about 30 degrees to about90 degrees relative to the spine 636, and more preferably angled atabout 60 degrees relative to the spine 636. Between the angled teeth 634are slots 638. Each slot 638 has an opening or pitch of about 5 degreesto about 35 degrees as measured between the proximal wall 640 of onetooth 634 a and the distal wall 642 of an adjacent tooth 634 b, and morepreferably about 20 degrees, as illustrated in FIG. 92.

The angled teeth 634 are angled in a proximal direction or in adirection away from the tissue in which it is inserted. Because theteeth 634 are angled away from the tissue, the angled teeth slidesmoothly past the tissue as the distraction device 632 is inserted,thereby reducing the risk of the distraction device getting caught orbeing hung-up on tissue during insertion. The angle teeth 634 also canfunction to resist retraction or withdrawal of the distraction device632 once it is deployed into tissue. For instance, if the distractiondevice 632 is moved in a direction to retract the distraction devicefrom tissue, the teeth 634 engage the tissue to resist such retraction.This resistance to retraction or reverse movement aids in preventingradial dilation of the distraction device after the distraction devicehas been deployed.

As illustrate in FIG. 91, as the distraction device 632 is wound to formthe distraction device support structure 640, the tips 633 of the teeth634 of the distraction device move closer together and close down orreduce the size or pitch of the slots 638 in between the teeth. Themoving of the teeth 634 into a closer configuration results in thedistraction device 632 being more dense (more material, less open space)towards the middle portion of the support structure 640. The denserdistraction device 632 adds stability to the center of the supportstructure 640 and aids in increasing the support structure's ability towithstand higher compressive forces in the axial direction.

FIGS. 93 and 94 illustrate an alternative embodiment of a distractiondevice 642 having teeth 644 and slots 646. In this embodiment, theopening or pitch of the slots 646 are reduced to about 14 degrees (asshown in FIG. 94). As illustrated in FIG. 93, as the distraction device642 curves to form the distraction device support structure 648, thetips 647 of the teeth 644 are optimized to almost completely close slots646. In one embodiment, the tips of the teeth contact adjacent teeth tocompletely close slots 646. Such a configuration results in adistraction device 642 that is denser than the immediate previousembodiment and provides more stability to the center portion of thesupport structure 648.

FIGS. 95-98 illustrates another embodiment of a distraction device 650that can include features that result in the distraction device forminga distraction device support structure 652 that has a uniform or flatend surface 654. Referring to FIG. 96, in one embodiment of thedistraction device 650, the distal end portion 656 of the distractiondevice includes an angled or sloped first section 658 that has a lengththat is equal to the length required for one revolution or to form onewinding. The distal tip 660 of the first angled section 658 ispreferably generally smaller than about half the height of the majorityof the distraction device, and the proximal end portion 662 of the firstangle section 658 is preferably the same height of the majority of thedistraction device. Proximal to the first angled section 658 is a secondangled or sloped section 664 that has generally the same size and shapeas the first angled section 658.

Turning to FIG. 97, the distraction device 650 is advanced over a coiledguide member 668, and as the first winding or loop 670 of thedistraction device is formed, the distal tip 660 of the first angledsection 658 nests into the second angled section 664 so that the end 654of the support structure 652 will be uniform or flat. After the firstwinding 670 is formed, the distraction device 650 is further advancedalong the guide member 668 to form the rest of the distraction devicesupport structure 652 with the end surface 654 remaining in a flat oruniform configuration as illustrated in FIG. 98. The uniform or flatconfiguration of the end 654 of the support structure 652 provides foreven distraction of the tissue layers and uniform or even contactbetween the distraction device support structure and the tissue layers.

Depending on the procedure, sometimes it is necessary for the guidemember to traverse or bore through tissue, such as cancellous bone. Forsuch applications, the distal end portion of the guide member can beconfigured to reduce the amount of penetration force required forinsertion of the guide member. For example, the distal end portion ofthe guide member can be designed to reduce the amount of frictionbetween the tissue and the guide member.

Referring to FIG. 99, in one embodiment, the guide member 676 includesan outer elongated member 678 that has a lumen therethrough. An inner orcentral elongated member 680 extends through the lumen and past thedistal end portion 682 of the outer elongated member 678. Both the outerelongated member 678 and the inner elongated members 680 can be made ofa shape memory material that has a natural coil or spring-like shape.Alternatively, either the outer elongated member 678 or the innerelongated member 680 can be made of a shape memory material. As such,the guide member can have a linear configuration for deployment and anon-linear configuration in-situ.

The inner member 680 is rotatable within the lumen of outer member 678,and the proximal end portion 684 of the inner member 680 is operativelyconnected to a rotational driving motor 686. The rotational drivingmotor 686 drives the inner member 680 to rotate relative to the outermember 678. The distal end portion 688 of the inner member 680 can alsoinclude a pointed tip for penetrating tissue.

To deploy the guide member 676, the distal end portion 688 of the innermember 680 is inserted into tissue, and the rotational driving motor 686is activated to cause the inner member 680 to rotate relative to theouter member 678. The rotational movement of the inner member 680 istranslated to distal end portion 688 of the inner member to create adrilling action for penetrating the tissue. Because the inner member 680is cover by the outer member 678, the tissue adjacent the outer member678 is substantially unaffected by the rotational movement of the innermember 680. The guide member 676 is advanced into tissue or betweentissue layers until the guide member has formed the desired number ofloops or has reached the desired height.

The immediately above-described guide member, as well as, any of theother guide members described herein can have a distal end portion thatis configured easily penetrate tissue. For example, FIG. 100 illustratesa distal end portion 690 of a guide member 692 that includes a ball orspherically shaped distal end portion that has a cross-section that islarger than the cross-section of the remaining portion of the guidemember.

FIG. 101 illustrates a distal end portion 696 of a guide member 698 thathas a generally pointed or spear-like shape.

FIG. 102 illustrates a distal end portion 700 of a guide member 702 thathas a generally duck-billed shape.

FIGS. 103 and 104 illustrate an embodiment of a guide member 704 thatincludes a cutting surface 708 located at the distal tip 710 of theguide member and an extendable/retractable cutting member 706. Theextendable/retractable cutting member 706 includes a catch 712 and acutting edge 714. Prior to advancement through tissue, the cuttingmember 706 is in a first or retracted position in which the cuttingmember is located in a recess or pocket 720 of the guide member 704.When guide member 704 is advanced through tissue, catch 712 contacts orcatches on the tissue, causing cutting member 706 to rotate about hinge716 and extend outwardly out of recess 720, as shown in phantom in FIG.104.

As the guide member 704 is further advanced through the tissue, thecutting edge 714 of extendible member 706 cuts the tissue adjacent thepath of the guide member, thereby weakening the structural integrity ofthe tissue surrounding the guide member. After a desired amount of theguide member 704 has been deployed, an implant, such as a distractiondevice, can be deployed over the guide member. Because extendible member706 has weakened the structural integrity of the tissue surroundingguide member 704, less drive force is required to advance the implantthrough the tissue and along the guide member.

After deployment of the implant, the guide member 704 is withdrawn fromthe tissue. As the guide member 704 is withdrawn, the back wall 718 ofextendible member 706 contacts the implant and/or the surroundingtissue, which forces the extendible member 706 to retract back intorecess 720. With extendible member 706 retracted, the guide member iseasily removed from the tissue and implant without any interference fromthe extendible member.

FIG. 105 illustrates a cutting device 730 that is adapted to be advancedalong a guide member that has been previously deployed within tissue.Cutting device 730 includes a passageway 732 extending along an axis X₁of the cutting device. Passageway 732 is adapted to receive a guidemember for mounting and advancing cutting device 730 along the guidemember. Cutting device 730 also includes at least one cutting edge orblade 734 that extends from cutting device 730 in a directionperpendicular to axis X₁.

Referring to FIG. 106, a guide member 736 is deployed into thecancellous bone 738 of a vertebral body 740. After guide member 736 hasbeen deployed, cutting member 730 is distally advanced over guide member736. In one embodiment, cutting member 730 can be advanced and retractedby a pusher member 743 operatively connected to a proximal end portion742 of the cutting member 730. As cutting member 730 is advanced alongguide member 736, cutting edges 734 cut the cancellous bone tissueadjacent the guide member, thereby weakening the structural integrity ofthe surrounding bone tissue. After cutting member 730 has been advancedalong guide member 736 a desired distance, the cutting member 730 isretracted back along the guide member 736 and removed. For example,pusher member 743 can be retracted or pulled distally to retract thecutting member 730 back along the guide member. A spinal implant, suchas any of the spinal implants described herein, can be deployed alongguide member 736. Because cutting member 730 has weakened the structuralintegrity of the tissue surrounding guide member 736, less drive forceis required to advance the implant through the tissue and along theguide member.

The normal intervertebral disk has an outer ligamentous ring called theannulus surrounding the nucleus pulposus. The annulus binds the adjacentvertebrae together and is constituted of collagen fibers that areattached to the vertebrae and cross each other so that half of theindividual fibers will tighten as the vertebrae are rotated in eitherdirection, thus resisting twisting or torsional motion.

Occasionally fissures may form rents through the annular wall. In theseinstances, the nucleus pulposus is urged outwardly from the subannularspace through a rent, often into the spinal column. Extruded nucleuspulposus can, and often does, mechanically press on the spinal cord orspinal nerve rootlet. This painful condition is clinically referred toas a ruptured or herniated disk. FIG. 113 illustrates an intravertebraldisk 750 shown above a vertebral body 752. Disk 750 includes an annulus754 and a nucleus 756 contained therein. The annulus 754 has a ruptureor fissure 758 that could lead to a nucleus herniation. As explained ingreater detail below, the devices and methods disclosed herein can beused as a containment device for containing the nucleus of within thedisk and to prevent herniation or bulging of the nucleus through theannulus of the disk.

Referring to FIG. 114, in one method of treating an intervertebral disk762, a cannula 760 is placed through an access port into the disk 762and a guide member 764 is deployed through the cannula 760 into thedisk. As in the previous embodiments, the guide member 764 forms acoiled or spring-like shape within the disk. The coil-like configurationof guide member 764 substantially surrounds the disk nucleus 768.Preferably, the guide member is inserted in or along the outer perimeterof the nucleus 768 or the inner perimeter of the annulus 766. Morepreferably, the guide member is inserted substantially between thenucleus 768 and the annulus 766 and forms the coil-like shapetherebetween.

After the guide member 764 has been deployed, a containment device 770is inserted along the guide member 764 and into disk 762 to form a coilor spring-shaped barrier 772 that substantially surrounds and containsat least a portion of the nucleus 768, and preferably substantiallysurrounds and contains the entire nucleus, as illustrated in FIG. 115.The containment device 770 is advanced over the guide member 764 untilthe desired height or the desired number of windings is attained. Afterthe barrier 772 has been formed, the guide member 764 may be withdrawnfrom the barrier or may be cut or otherwise detach and left within thebarrier to add extra support and stability to the barrier. Referring toFIG. 116, the deployed barrier 772 substantially encircles the nucleus768 to contain the nucleus and prevent it from bulging or extrudingthrough the annulus 766.

The containment device 770 can have a variety of shapes andconfigurations. For example, the containment device 770 a could have arectangular cross-section as illustrated in FIG. 118. In anotherembodiment, the containment device has frictionally engaging surfacesthat engage to add in maintaining the shape of the barrier formed by thecontainment device. For example, the containment device 770 b may have agenerally V-shaped cross-section, as illustrated in FIG. 119, or thecontainment device 770 c may have the interlocking design illustrated inFIGS. 117 and 120.

The containment device of the present invention also can be used forannulus repair. Instead of treating a herniated disk by enclosing thenucleus, the containment device can be positioned along a damagedannulus to provide supported to the nucleus and annulus.

Referring to FIG. 121, a guide member 790 can be deployed through acannula 793 into the intervertebral disk 805 to form a coil-likestructure substantially around at portion of the nucleus 806.Preferably, the guide member 790 is inserted in or along the outerperimeter of the nucleus 806 or the inner perimeter of the annulus 808.More preferably, the guide member is inserted substantially between thenucleus 806 and the annulus 808 and forms the coil-like shapetherebetween. The guide member 790 forms a first winding 792 and asecond winding 794 within the disk 805. After the guide member 790 isdeployed, a containment device 796 is advanced along the guide member790, preferably by a pusher 798, as illustrated in FIG. 122. In thisembodiment, the containment device 796 is preferably smaller than aboutone full winding of the coil-like guide member, and can be substantiallysmaller than one full winding of the guide member. The containmentdevice 796 is advanced along the guide member into the disk 805 and ispositioned at a desired location along the second winding 794. Thecontainment device is positioned along the guide member 790 at alocation adjacent disk tissue in need of treatment or support. Forexample, in one embodiment, the containment device 796 is positionedadjacent a fissured portion of the annulus.

Optionally, the containment device can include a radiopaque marker sothat the positioning of the containment device can be monitored throughfluoroscopy. Furthermore, referring to FIG. 122, the pusher member 798can be a catheter like member that is also advanced over the guidemember 790. The pusher member 798 can also include a grasping or holdinggroove (not shown) that engages proximal end portion 800 of thecontainment member 796 and can control the orientation of thecontainment member by rotation of the pusher member. The pusher member798 could also include a releasable locking mechanism that secures thepusher member to the containment device 796 until the containment deviceis in the desired location.

After the containment device 796 is in the desired location along thesecond winding 794, optionally, a second containment device 802 isadvanced along the guide member 790 and positioned at a location on thefirst winding 792 which is above or beneath the first containment device796, depending of the orientation of the guide member, as illustrated inFIG. 124. When a second containment device is employed, the first andsecond containment devices 796, 802 engage each other to form a barrier804 that supports the nucleus 806 and annulus 808 and prevents thenucleus 806 from bulging through the damaged annulus 808. The guidemember 790 may be cut or otherwise detached and left in the disk asillustrated in FIGS. 124 and 125. Alternatively, the guide member 790may be removed from the barrier 804 as illustrated in FIG. 123.

In another embodiment of the present subject matter, a containment wirecan be employed to repair a ruptured annulus. Referring to FIG. 126, acannula 810 is introduced into the annulus 811 from a posterolateralapproach (or any other applicable approaches) on the inferior side ofthe annulus. Containment wire 812 is then deployed through the cannula810 and thread into and through the annulus 811, as illustrated in FIG.127. The containment wire is made of a shape memory material that has anatural coiled configuration when deployed through the cannula, thecontainment wire takes on a generally linear or constrainedconfiguration. As shown, the containment wire device 812 is advancedinto the annulus and through the annulus. As the containment wire 812 isadvanced out of the cannula and through the annulus, it returns to itscoiled configuration and creates several loops in annulus. The number ofloops depending on the height of the disk. The containment device 812provides a fence like structure that reinforces rupture line 814 toprevent any further bulging or herniation of the nucleus 816.

In another method of treating disk with the containment wire, thecontainment wire is deployed to form a coil shaped structure around atleast a portion of the nucleus, and preferably substantially around theentire nucleus. Similar to the deployment of the guide member of FIG.114, the containment wire can be deployed in or along the outerperimeter of the nucleus or the inner perimeter of the annulus.Preferably, the containment wire is deployed between the nucleus and theannulus. The containment device forms several loops that substantiallysurround the nucleus to create coil shaped fence-like structure thatsubstantially contains the nucleus within the annulus.

FIG. 132 illustrates another embodiment of the containment wire in whichthe containment wire comprises wavy wire 818. FIGS. 128-131 illustrateone embodiment of a method of introducing a wavy containment wire intoan annulus of a disk. FIG. 128 illustrates one embodiment of adeployment system 820 for deployment of the wavy containment wire 818.Deployment system 820 includes a deployment cannula 822, a guide member824 and a guide catheter 826. Referring to FIG. 129, the guide member824 is similar to the guide member described above and has a lineardeployment configuration and coil shaped deployed configuration. Theguide member 824 is deployed through the cannula 822 to from a coiledshaped portion 828 within a treatment site. After a desired amount ofthe guide member 824 has been deployed, the guide catheter 824 isadvanced over the guide member 824, as illustrated in FIGS. 129 and 130.The guide member 824 then is removed from the guide catheter 826,leaving the guide catheter in the treatment site.

The wavy containment wire 818 also is comprised of a shape memorymaterial and includes a straight deployment configuration and the coiledwavy configuration illustrated in FIG. 132. The wavy containment wire818 is deployed through the deployment catheter 826 in the generallystraight deployment configuration. The wavy containment wire 818 is heldor constrained in the straight configuration by the guide catheter 826.Once the desired amount of the wavy containment wire 818 has beenadvanced into the guide catheter 826, the guide catheter is withdrawndistally, as shown in FIG. 131, to allow the containment wire 818 toreturn to its wavy configuration in-situ.

Although the present invention is described in light of the illustratedembodiments, it is understood that this for the purposes illustrationand not limitation. Other applications, modifications or use of thesupport or distraction device may be made without departing from thescope of this invention, as set forth in the claims now or hereafterfiled.

1.-20. (canceled)
 21. A device for treating the spine, comprising: agenerally elongated guide member adapted for insertion into spinaltissue, the guide member having a proximal end portion and a distal endportion, said distal end portion of the guide member defining agenerally helical configuration when inserted into the spinal tissue;and a generally elongated implant having opposed top and bottom surfaceswherein one of the top surface and the bottom surface has a plurality ofaxially spaced apart projections extending from the surface and theother of the surfaces includes a plurality of axially spaced apartrecesses, the implant being advanceable along the guide member forinsertion into the spinal tissue and advanceable along and conforming tothe generally helical configuration of the distal end portion of theguide member so that the elongated member defines a generally helicalstructure including a plurality of adjacent windings wherein windingsare in contact with immediately adjacent windings and the projections ofone of the top surface and the bottom surface of the elongated implantengage the recesses of the other surface.
 22. The device of claim 21 inwhich the top and bottom surfaces of the implant include knurls thatdefined the projections and recesses.
 23. The device of claim 21 inwhich the top surface includes the projections and the bottom surfaceincludes the recesses.
 24. The device of claim 21 in which the bottomsurface includes the projections and the top surface includes therecesses.
 25. The device of claim 21 in which the projections comprise agenerally rectangular cross-section.
 26. The device of claim 21 in whichthe distal end portion of the generally elongated guide member comprisesa generally linearly configuration for insertion between the tissuelayers and changes into the generally helical configuration between thetissue layers.
 27. The device of claim 21 in which the engagementbetween the projections and recesses reduces dilation of windingsrelative to the immediately adjacent windings of the generally helicalstructure.
 28. The device of claim 21 further including a retainingmember configured to secure immediately adjacent windings of the helicalstructure to one another.
 29. The device of claim 28 wherein theprojections and portions of the implant between recesses include holesthat align when the projections and recesses are engaged, and theretaining member is configured to be inserted through the holes.
 30. Thedevice of claim 21 in which the projections are movable relative totheir respective surface between a first, unengaged position in whichprojections are unengaged with the recesses and a second, engagedposition in which projections are engaged with the recesses.
 31. Thedevice of claim 30 in which the projections are biased toward theengaged position.
 32. The device of claim 31 in which the projectionsare biased toward the engaged position by weighting of the projection ora spring.
 33. The device of claim 31 in which the projections areconfigured to be maintained in the unengaged position until after theimplant defines the helical structure.
 34. The device of claim 31 inwhich the implant includes a passageway therethrough for receiving theguide member and advancement thereover, wherein portions of theprojections extend into the passageway and the guide member contacts theportions of the projections to maintain the projections in the unengagedposition, and when the guide member is removed from the passageway, theprojections move to the engaged position.
 35. An implant for treatingthe spine, comprising: a generally elongated member being movablebetween a generally liner configuration for insertion between spinaltissue and a generally helical, implanted configuration including aplurality of adjacent windings wherein windings are in contact withimmediately adjacent windings, the generally elongated member havingopposed top and bottom surfaces wherein one of the top surface and thebottom surface includes a plurality of axially spaced apart recesses,and the other of the surfaces includes a plurality of axially spacedapart projections that are moveable relative to the other of thesurfaces; and when in the generally helical, implanted configuration,the projections being movable from an unengaged position to an engagedposition wherein the projections engage the recesses.
 36. The implant ofclaim 35 in which the projections are biased toward the engagedposition.
 37. The implant of claim 36 in which the projections arebiased toward the engaged position by weighting of the projections or aspring.
 38. The implant of claim 36 in which the projections areconfigured to be maintained in the unlocked position until after theelongated member forms the generally helical, implanted configuration.39. The implant of claim 38 in which the elongated member includes apassageway extending therethrough for receiving a second elongatedmember therein, wherein portions of the projections extend into thepassageway and the second elongated member contacts the portions of theprojections to maintain the projections in the unengaged position untilthe second elongated member is removed from the passageway.
 40. Theimplant of claim 35 in which the projections are at or below level withthe other one of the surfaces when in the unengaged position.